K to 12 mechanical drafting learning module

Republic of the Philippines
DEPARTMENT OF EDUCATION

K to 12 Basic Education Curriculum
Technology and Livelihood Education
Learning Module

MECHANICAL DRAFTING
EXPLORATORY COURSE
Grades 7 and Grade 8

TABLE OF CONTENTS
Page
What Is This Module About ? .................................................................................... 2
How Do You Use This Module .................................................................................. 3
LESSON 1 – Prepare Drafting Materials and Tools/Drawing Instrument 4
LESSON 2 – Perform Basic Mensuration and Calculation ............................. 32
LESSON 3 – Interpret Working Plans and Sketches ......................................... 72
LESSON 4 – Apply Safety Practices.................................................................... 143
Answer Keys ............................................................................................................... 179
List of Materials /Tools/Equipment /Consumables for this Module ................ 190
Acknowledgment ...................................................................................................... 191

MECHANICAL DRAFTING
K to 12 – Technology and Livelihood Education

1

What Is This Module?
About?
Welcome to the world of MECHANICAL DRAFTING!
This Module is an exploratory course which leads you to Mechanical Drafting
National Certificate Level II ( NC II)1. It covers 4 common competencies that a Grade 7 /
Grade 8 Technology and Livelihood Education (TLE) student like you ought to possess,
namely:
1.
2.
3.
4.

Prepare Drafting Materials and Tools/Drawing Instruments
Perform Basic Mensuration and Calculation
Interpret Working Plans and Sketches
Apply Safety Practices

These 4 common competencies are covered separately in 4 Lessons. As shown
below, each Lesson is directed to the attainment of one or two learning outcomes:
Lesson 1 – Prepare Drafting Materials and Tools/Drawing Instruments
LO 1. Identify drafting materials and tools/drawing instruments applicable to
a specific job
LO 2. Request, receive and inspect drafting materials and tools/drawing
instruments
Lesson 2 – Perform Basic Mensuration and Calculation
LO 1. Select and use measuring instruments
LO 2. Clean and store measuring instruments
LO 3. Convert fraction to decimal and vice versa
LO 4. Convert English to Metric Measurement vice versa
Lesson 3 – Interpret Working Plans and Sketches
LO 1. Identify assembly and detailed drawing.
Lesson 4 – Apply Safety Practices
LO 1. Identify hazardous area
LO 2. Use personal protective clothing and devices
Your success in this exploratory course on Mechanical Drafting is shown in your
ability to perform the performance standards found in each Lesson .

1NATIONAL

CERTIFICATE (NC) is a certification issued to individuals who achieved all the required units of competency for a national
qualification as defined under the Training Regulations. NCs are aligned to specific levels within the PTQF. (TESDA Board Resolution
No. 2004-13, Training Regulations Framework)
NATIONAL CERTIFICATE LEVEL refers to the four (4) qualification levels defined in the Philippine TVET Qualifications Framework
(PTQF) where the worker with:
a. NC I performs a routine and predictable tasks; has little judgment; and, works under supervision;
b. NC II performs prescribed range of functions involving known routines and procedures; has limited choice and complexity of
functions, and has little accountability;

MECHANICAL DRAFTING

2

How Do You Use This Module?
This Module has 4 Lessons. Each Lesson has the following parts.
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Learning Outcomes
Performance Standards
Materials
Definition of Terms
What Do You Already Know?
What Do You Need to Know?
How Much Have You Learned?
How Do You Apply What You Learned?
How Well Did You Perform?
How Do You Extend Your Learning?
References

To get the most from this Module, you need to do the following:
1. Begin by reading and understanding the Learning Outcome/s and Performance
Standards. These tell you what you should know and be able to do at the end of this
Module.
2. Find out what you already know by taking the Pretest then check your answer
against the Answer Key. If you get 99 to 100% of the items correctly, you may
proceed to the next Lesson. This means that you need not go through the Lesson
because you already know what it is about. If you failed to get 99 to 100% correctly,
go through the Lesson again and review especially those items which you failed to
get.
3. Do the required Learning Activities. They begin with one or more Information
Sheets. An Information Sheet contains important notes or basic information that you
need to know.
After reading the Information Sheet, test yourself on how much you learned
by means of the Self-check. Refer to the Answer Key for correction. Do not hesitate
to go back to the Information Sheet when you do not get all test items correctly.
This will ensure your mastery of basic information.
4. Demonstrate what you learned by doing what the Activity / Operation /Job Sheet
directs you to do.
5. You must be able to apply what you have learned in another activity or in real life
situation.
6. Accomplish the Scoring Rubrics for you to know how well you performed.
Each Lesson also provides you with references and definition of key terms for your
guide. They can be of great help. Use them fully.

If you have questions, ask your teacher for assistance.

MECHANICAL DRAFTING

3

LESSON 1
Prepare Drafting Materials and
Tools/Drawing Instrument
.

LEARNING OUTCOMES:
At the end of this Lesson, you are expected to
do the following:

LO 1. identify drafting materials and tools/drawing instruments applicable
to a specific job
LO 2. request, receive and inspect drafting materials and tools/drawing
instruments
MECHANICAL DRAFTING

4

Definition of Terms
Assembly drawing – a drawing that shows how different parts go together
Compass – an instrument used when drawing arcs and circles
Delivery receipt – a form that shows proof or receipt of goods or services
Detailed drawing – a drawing showing a single part of a machine
Dimensioning – the process of placing measurements in a drawing in the Metric or
English system
Divider – a drawing instrument used when transferring measurements, dividing lines,
arcs into the desired number of equal parts
Drawing – a picture, diagram made of lines, a graphic representation of real thing,
an idea or a design for production or construction
Drawing pencil – one of the most important tools of a draftsman, used for drawing
English system – a system of linear measurement where it is based on standard
foot
Erasing shield – used when clearing up smudges, unnecessary pencil lines
Geometrical construction – the process wherein geometric problems are solved
accurately in mechanical drawings
Mechanical drafting – a process for making accurate drawings using special
drawing tools and instruments
Metric system – a system of linear measurement which it is based on the standard
meter
Orthographic drawing – the object is presented into two or more views by
projecting the outline into the planes of projection
perpendicular to each other
Pictorial view – the presentation of an object where it is viewed showing the three
faces of an object are shown
Protractor – used for determining gradations of the degrees when measuring arcs
and circles
Requisition form – an official form, a printed document on which a request is made
Sketch – a quickly executed freehand drawing that is not intended as a finished work
Triangular scale – a tool generally used when reproducing a drawing in an enlarged
or reduced version to some regular proportion
T-Square – a drawing instrument used when drawing horizontal and vertical lines

Acronyms
EDP System – Electronic Data Processing System

MECHANICAL DRAFTING

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LEARNING OUTCOME 1
Identify drafting materials and tools/drawing instruments
applicable to a specific job.

PERFORMANCE STANDARDS
1. Drafting materials and tools/drawing instruments are identified per job
requirements.
2. Materials and tools/drawing instruments are classified according to their uses
to a specific drafting project.

Materials

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T- square
Triangles 30 x 60 and 45 x 45
Pencils/ mechanical pencils
Compass/ Divider
Drawing paper
Drawing board
Triangular Scale
Eraser
Erasing shield
Protractor
Sharpener
Drawing Tape

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Let us determine how much you already know about drafting materials and
tools/drawing instruments. Take this test.

Pretest LO 1

Direction:

Select the drafting material and tool/drawing applicable to a specific job.

1. A drafting tool used for drawing horizontal lines
A. Compass B. Triangle

C. T- square

D. Triangular Scales

2. Drafting material used for fastening the drawing paper on the drawing table
A. Compass

B. Divider

C. Masking Tape

D. Triangle

3. The main function of this tool is to reproduce the measurements of an object to any
size.
A. Compass B. Protractor

C. Triangle

D. Triangular Scales

4. This drafting tool is used to protect the rest of the drawing when removing
unnecessary lines.
A. Erasing Shield

B. Eraser

C. Masking Tape

D. Pencil Sharpener

5. This drafting tool is used when drawing vertical lines.
A. Compass

B. Triangle

C. Triangular Scales D. Ruler

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Direction:

Match Column A with Column B. Write only the letter of the correct answer on
a separate sheet of paper.

Column A

Column B

1. Type of pencils when extreme accuracy is required

A. Eraser

2. Used to clean the dirt off the drawing

B. Medium pencils

3. An instrument used for transferring measurements

C. Protractor

4. Type of pencils used for general purpose in drawing

D. Divider

5. Best tool when measuring arcs, angles and circles

E. Hard pencils
F. Triangle

Now check your answers using the Answer Key. If you got 90-100% of the
items correctly, proceed to the next Learning Outcome. If not, do the next
activity/ties again to gain knowledge and skills required for mastery.

MECHANICAL DRAFTING

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What Do You Need To Know?
Read Information Sheet 1.1 very well then find out how much you can
remember and how much you learned by doing Self-check 1.1.

Information Sheet 1.1

DRAFTING MATERIALS AND TOOLS, ITS USES/FUNCTIONS
There are a great variety of drafting materials and tools used in mechanical
drawing. The drafting materials and tools discussed in this Module include most of the basic
ones but sufficient enough for your initial understanding about mechanical drawing.

PICTURES/ILLUSTRATIONS

MATERIALS,DESCRIPTION AND FUNCTION

Drawing paper

Drawing paper

Various types of drawing papers are available for use
but hard and soft surface drawing papers are highly
recommended to be the best. This type does not groove
easily when pressure is applied to the pencil. Oslo
paper is commonly used but bond paper is also
recommended.

Masking tape
This is used for fastening the drawing paper on the
drawing table or drawing board because it does not
damage the board and it will not damage the paper if it is
removed by pulling it off.
Masking Tape

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Pencil sharpener
Pencils should be sharpened whenever they show sign of
dullness. Various types and designs are available in the
store for use.
Pencil sharpener
Eraser
This is used to clean the dirt off the drawing. A soft eraser
is advantageous in removing smudges and pencil marks,
whereas, a harder eraser is useful for making changes
and correcting errors in the drawing.
Eraser

Drawing pencil
This is one of the most important tools in drawing. It
comes in various grades. The grade of pencil to be used
depends on the quality of paper to be used. You have to
take into consideration also the type of line work required.
Hard Range

Hard pencils – are used where extreme accuracy is
required especially working on graphs, diagrams and
charts.
Medium pencils – are used for general purpose work in
drawing.

Medium Range

Soft pencils – are too soft to be used in mechanical
drafting. They are very useful for art work of various kinds.

Soft Range

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Triangular Scales

Triangular Scales

This is a tool generally used when reproducing a drawing
in an enlarged or reduced form to some regular proportion.
The architect’s scale is the most commonly used for
general drawing. Its main function is to reproduce the
measurements of an object in full size, reduced size, and
enlarged size.

Erasing Shield
This tool is made up of metal with irregular holes. It is a
useful tool to protect the rest of the drawing when clearing
up smudges, unnecessary pencil lines and other erasures.
Erasing Shield

DRAWING INSTRUMENTS
Drawing instruments are used for drawing and designing purposes. Their quality is
very essential if you want to have good result. Cheaper drawing tools and instruments do
not only provide poor quality results but also do not last long. You have to observe proper
handling and care if you want them.

PICTURES/ILLUSTRATIONS

MATERIALS AND TOOLS DESCRIPTION

T-Square
It is a drawing instrument used when making
horizontal lines. It is also used for guiding triangles when
drawing vertical lines. It is made of wood, plastic or the
combination of both. There are three (3) types of Tsquare, namely:
1. Fixed Head. The head is fastened to the blade. It is
used for ordinary work.
2. Movable Head or Adjustable Head. It has one fixed
and one adjustable head and used only for occasional
drawing.
3. Detachable Head or Removable Head. It is designed
for comfort when carrying the T-square.

MECHANICAL DRAFTING

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Triangle
It is a three-sided ruler, which typically has two
equal sides meeting at a 90 degree angle and to a third
side at 45, 30, including 60 degree angles. It is usually
made of plastic and comes in different sizes. If in use,
the base of the triangle must rest on the blade of the Tsquare. Drawing a line always starts from the point near
the base going upward. Commonly used triangles are:
a. 30 degrees X 60 degrees
b. 45 degrees X 45 degrees

Compass
This drawing instrument is used when drawing
arcs and circles. It is used in a similar way to a divider. It
is composed of one with the pen leg and the needle
point leg being held together with a handle. This drawing
instrument can be used for both penciling and inking.

Divider
This is a drawing instrument used when
transferring measurements, dividing lines and arcs into
the desired number of equal parts. It can easily transfer
accurate measurements by adjusting the divider points.
Constant correct practice is necessary before doing an
actual work for a quick and easy control when use.

Protractor

Protractor

It is a semi-circular instrument divided into
180 equal parts, each of which is called a degree. It is
used to determine gradations of the degrees when
measuring arcs, angles and circles. High quality
protractor is usually made of plastic.

Did you enjoy reading the given information? Which among the drafting
materials, and drawing tools and instruments matter to you most? Well, you are
just starting how. Let’s move ahead to enrich your understanding.

MECHANICAL DRAFTING

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Self-Check 1.1
Directions: There are twelve (12) different drafting materials and tools and drawing
instruments that can be found in the puzzle. Identify at least ten (10) of
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Refer to the Answer Key. What is your score?

MECHANICAL DRAFTING

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How Do You Apply What You Have Learned?
It is not enough that you learned concepts on drafting materials and
drawing instruments. Be sure that you are also able to demonstrate the
skills. Do this Activity Sheet.

Activity Sheet 1.1

Proper Manipulation of the T-square
Directions: Below is a simple activity for you to work on. Practice the task following the
given procedure.

Instrument:


T – Square

Equipment:


Drawing Table (Drafting Table or Drawing Board)

Procedure:
1. Place the head of the T-square against the edge of the drafting table. (Left side of
the table if you are right handed and at the right side of the table if you are left
handed).
2. Slide the working head of the T-square against the working edge of the drawing
table. The two edges should be in constant contact until the desired position.
Note: Do not use the T-square on an uneven or rough surfaces and never cut paper
along its working edge.

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For Right-handed

For Left-handed

Proper use of T-Square

Setting up Drawing Paper on the Drawing Table

given procedure.
Materials:



Drawing paper
Masking tape

Instrument:


T – Square

Equipment:


Drawing Table

MECHANICAL DRAFTING

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Procedure:
1. Press firmly the T-square against the working edge of the drawing table.
2. Place the drawing paper close to the working edge of the drawing table and
working head of the T-square depending on you if you are right or left-handed,
while the paper is placed on top edge of the T-square.
3. Fasten the upper left portion of the drawing paper followed by the lower right
portion and finally the remaining corners.
Note: Always fasten larger backing sheet of thicker drawing paper on the board first.

Placing drawing paper to the drawing board

Drawing a Horizontal Line

given procedure.
Materials:

Drawing paper

Masking tape
Instrument:

T – Square

Triangles (30 deg. x 60 deg. and 45 deg. x 45 deg.)
Equipment:

Drawing Table

MECHANICAL DRAFTING

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Procedure:
1. Press the head of the T-square against the working edge of the drawing table and
lean the pencil to the desired direction of the line inclined at more or less 60
degrees with the drawing table.
2. Maintain the position of the pencil while you glide lightly on the blade of the Tsquare.
3. Draw the line from left to right rotating occasionally to produce uniform line
weights.
(Reverse this step if you are left-handed).

Using the T-Square to draw Horizontal lines
Drawing a Vertical Line
given procedure.
Materials:
 Drawing paper
 Masking tape
Instrument:
 T – Square
 Triangles (30 deg. x 60 deg. and 45 deg. x 45 deg.)
Equipment:
 Drawing Table

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Procedure:
1. Use 45 degrees triangle or 30 degrees x 60 degrees to draw vertical lines.
2. Place the triangle on top of the blade of the T-square with the vertical edge on the
left.
3. With the left hand pressing the T-square and the triangle against the drawing
board, draw the line upward, rotating the pencil slowly between the thumb and
forefinger.
See figure below.

Drawing vertical lines using triangles and T-square

How did you find the activities? Did you enjoy doing them?
Did you find them difficult? Challenge yourself by keeping on
practicing correctly the given steps in each activity. Have fun!

MECHANICAL DRAFTING

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Find out by accomplishing the Scoring Rubric honestly and sincerely.
Remember it is your learning at stake!

Learner's Name:

Date:

Competency:

Test Attempt
1st

Directions:

Ask your teacher to
assess your
performance in the
following critical task and
performance criteria
below

2nd

3rd

OVERALL EVALUATION

Level
Achieved

PERFORMANCE LEVELS
4 - Can perform this skill without
supervision and with initiative and
adaptability to problem situations.
3 - Can perform this skill satisfactorily
without assistance or supervision.

You will be rated based
on the overall evaluation
on the right side.

2 - Can perform this skill satisfactorily but
requires some assistance and/or
supervision.

1 - Can perform parts of this skill
satisfactorily, but requires considerable
assistance and/or
supervision.
Note: Instructor will initial level achieved.

MECHANICAL DRAFTING

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Yes

Y
No

N/A

For acceptable achievement, all items should receive a "Yes"
or "N/A" response.

After gaining knowledge from the previous activities, you are
ready to learn about official documents and other related forms
pertaining to involve when you need drafting materials, drawing tools
and instruments needed in preparing mechanical drawings. Now proceed
to another learning experiences. Enjoy and have fun!

MECHANICAL DRAFTING

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LEARNING OUTCOME 2
Request, receive, inspect and store drafting materials and
tools

1.
2.
3.

Received and inspected materials and tools per quantity and
specification based on requisition.
Tools and materials are checked for damages and manufacturing
defects.
Received materials and tools/instruments are handled with appropriate
safety devices.

Materials



Sample forms in requesting, receiving, inspecting and storing drafting materials and
tools,drawing instrument

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Let us determine how much you already know about requesting, receiving and
inspecting drafting materials and tools/drawing instruments. Take this test.

Pretest LO 1

Directions: Read the statement carefully. Write the letter of the correct answer on a
separate sheet of paper.
1. This form shows proof or receipt of goods or services.
A. delivery receipt form
C. purchase order form
B. inventory form
D. requisition slip form
2. This form contains specified quantities of described goods at agreed terms and at a
designated time and place.
B. inventory form


3. This form is a printed document on which a request is made.
B. inventory form

4. This form contains information about name, number, purchase information and cost of
goods and displays on a balance sheet.
B. inventory form
5. This department is in-charge of unloading, unpacking of incoming materials, check,
identify goods received with descriptions on the purchase order.
A. accounting department
C. receiving department
B. budget department
D. sales department
Compare your answers using the Answer Key. If you got 90-100% of
the items correct, that means you are already familiar with the lesson
covered by Learning Outcome No. 2. Therefore you can proceed to the next
activity.
If you got many items wrong, study the lesson again. Carefully
reviewing the lesson helps you understand the concepts better. This also
helps you learn the skills to mastery level. Concentrate on the parts that
cover the questions you missed. After this, you are very much ready to
proceed to the next learning activity.
MECHANICAL DRAFTING

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Read the Information Sheet very well then find out how much you can


PROCEDURES IN RECEIVING AND STORING TOOLS AND MATERIALS
The Receiving Department has the function to unload and unpack incoming
materials; check quantities received against the shippers packing list; identify goods
received with descriptions on the purchase order; prepare a receiving report; notify the
purchasing department of descriptions discovered; arrange for inspection when necessary;
notify the purchasing department of any damage in transit; and rout accepted materials to
the appropriate manufacturer’s location.
The form also provides a space for the inspection department to note either the
complete approval of the shipment or the quantity rejected and the reason for the rejection,
in inspection does not take place immediately after receipt of the materials, the receiving
report is distributed as follows:
The receiving department keeps one copy and sends another copy to the purchasing
department as notice of the arrival of the materials.
All other copies go to the inspection department, and are distributed when inspection
is completed. After inspection, one copy of the receiving report, with the inspection result is
sent to the accounting department, where it is matched with the purchase order and the
venders invoice and the paid. Other copies go to various departments such as materials and
production planning. One copy accompanies the materials, so that the storekeeper knows
the quantity and the kind of materials received.
INVENTORY
Inventory is an idle stock of physical goods that contain economic value, and are
held in various forms by an organization in its custody awaiting packing, processing,
transformation, use or sale in a future point of time
INVENTORY FORM
The Inventory form contains information about items (name, number, sales and
purchase information, and cost of goods sold account information) that any business
purchases for sale, tracks in inventory, and displays on a balance sheet.
MECHANICAL DRAFTING

23

VARIOUS FORMS
Accurate entry in different forms used in drafting works is essentially important in
order to purchase right, accurate and complete number of drawing materials, tools and
instruments needed in a specific drafting job. Here are sample various forms used in
drafting works.

A. Sample Requisition Slip Form
This is an official paper in the form of a printed document on which a request in
made.
Name:
Project:
Classification:
Purpose:
NO.

QUANTITY

_____________
Requisitioner

UNIT

DESCRIPTION

_______________
Teacher

MECHANICAL DRAFTING

UNIT
PRICE

________________
Department Head

TOTAL
PRICE

________________
Principal

24

B. Sample Purchase Requisition Form

Below is a sample purchase requisition form. For standard materials, little
information other than the stock number may be needed and for other purchases
requests, it may be necessary to give particular descriptions, blueprints, catalog
numbers, weights, standards, brand names, exact quantities to order, and suggested
prices. One copy remains with the originating employee, and the original is sent to
the purchasing department for execution of the request.
Purchase Requisition

To Purchasing Department
Deliver to _________________

Date Required___________________
Dept No. ________________

Acct. No. _______________

Suggested Supplier________________________________________________________________

Qty

Item No.

Description

Unit Price

Amount

Budget Control

Allowance for period ____

Balance Available___

Ordered By____

Amt This Purchase___ Approved By___

Remaining Balance___

MECHANICAL DRAFTING

25

C.

Sample Delivery Receipt Form
Delivery receipt form shows proof or receipt of goods or services. The receiver
acknowledges receiving a consignment of goods from supplier. The buyer signs it
before it is returned to the seller. This officially takes care of uncertainties on the part
of the supplier who gets to know the safe and timely arrival of goods to their designated
destination.
Name of Supplying Company:
Delivery Receipt:
Supplier’s Address:
Date:

NO.

QUANTITY

DESCRIPTION

UNIT PRICE

TOTAL PRICE

I hereby acknowledge receipt of the following in perfect condition as per the
set of conditions of our supply contract from the firm of ____________________ (Name of
supplying company).

Order No.: ________________
Quantity

Description

Invoice No.: ______________
MECHANICAL DRAFTING

Remarks

Date actually received: _____________
26

D. Sample Inventory Form of Drawing Tools and Instruments

Name:
Year & Section:
School/Department:
Laboratory/Shop:
Purpose:
Tools/
Instruments

Qty.

_____________
Requisitioner

No. Of
Usable

No. Of Not
Usable But
Repairable

_______________
Teacher

No. Of
Condemn
-Able

No. Of
Borrowed

________________
Department Head

No. Of
Missing

________________
Principal

E. Sample Borrower’s Slip
Name of Borrower: __________________________
Description

________________________________
Signature of Borrower
Date Returned: ___________________

MECHANICAL DRAFTING

Date: __________________

Quantity

Remarks

Noted by:

________________________
Personnel In-Charge
27

Self-Check 1.2

TEXT TWIST
A.

Directions: Under column A are disarranged words or words of different forms used
in drafting when requesting, receiving and inspecting needed materials,
tools and instruments. Arrange it to form the correct word or words.
Column A
1.

ROIFYVT MNOENF

Column B
1. ________________________________

2. RLVCDPYT EEEEIIR

2. ________________________________

3. PRESO ROBRWIL

3. ________________________________

4. SODEAR CUPREAH

4. ________________________________

5. FITIMEON SIRUROQ

5. ________________________________

B. Direction: Describe briefly at least two (2) of your correct answers.
1. ________________________________________________________________
________________________________________________________________
________________________________________________________________
______________________________________________________________.
2. ________________________________________________________________
________________________________________________________________
________________________________________________________________
______________________________________________________________.

MECHANICAL DRAFTING

28

Congratulations!
You did a great job! Rest and relax a
while then move on to the next
lesson. Good luck!

REFERENCES
LO1






Giesecke, Mitchell and Spencer, Technical Drawing; The Macmillan Company:
1999
German M. Manaois, Drafting 1 and 2; Phoenix Publishing: 1983
Esguerra and Molino, Exploratory Drafting; Abiva Publishing: 1980
Stirling, Norman, Introduction to Technical Drawing, Metric Edition
http://www.images.search.yahoo.com/search/image



MECHANICAL DRAFTING

29

LESSON 2
Perform Basic Mensuration and
Calculation

3
0

3

0

0

0

a
b

l
t

ase
H

A

h
h

B

C
ONE

PYRA
MID

LEARNING OUTCOMES:
do the following:

LO 1. select and use measuring instruments;
LO 2. clean and store measuring instruments; and
LO 3. convert fraction to decimal and vice versa
LO 4. convert English to Metric measurement
MECHANICAL DRAFTING

30

Definition of Terms
Angle - geometrical figure composed of two straight lines intersecting at one of their
extremities
Calculation - act or process of or result of calculating
Circle - closed curve where all points are equally distant from the center
Concentric circles - consist of two or more circles with a common center.
Decimal - number expressed in a counting system that uses units of 10, especially a
decimal fraction
Dimension - measurable extent of length, thickness and width
Eccentric circles - circles having no common center.
English system – scaled in inches where one foot equals 12 inches.
Formula - special kind of equation. It is a mathematical rule expressing the
relationship of two or more quantities by means of numerals, variables and
operating symbols
Geometric shapes - characterized by straight lines, regular curves, and angles
Graduation - scale of a measuring tool
Mensuration – act of art of measuring
Metric system – system of measurement based on the meter
Perpendicular lines – lines which make a 900 angle with each other
Radius - length of a straight line connecting the center of a circle with a point on the
circumference of a circle.
Standard - measure of reference

MECHANICAL DRAFTING

31

LEARNING OUTCOME 1
Select and use measuring instruments

1. Measuring instruments are selected and used according to the level of
accuracy required.
2. Measurements taken are accurate to the finest gradation of the selected
measuring instrument.
3. Measuring techniques used are correct and appropriate to the instrument
used.

Materials











T- square
Compass
Drawing paper
Drawing board
Scale
Eraser
Erasing shield
Protractor

MECHANICAL DRAFTING

32

Let us determine how much you already know about the of measuring
instruments in mechanical drafting. Take this test.
Pretest LO 1
Directions: Multiple Choices. Write the letter of the correct answer.
1. A measuring tool used to layout an angle or an arc.
A. Compass
B. Divider
C. Protractor

D. Tape ruler

2. The most popular type of measuring tools, usually 6 or 12 inches in length.
A. Tape ruler
B. Triangle
C. Ruler
D. Scale
.
3. Its main purpose is to reproduce, reduce or enlarge the dimension of size on a drawing.
A. Tape ruler
B. Triangle
C. Ruler
D. Scale
4. It is used for drawing vertical and oblique lines.
A . Ruler
B. Scale
C. Triangle
D. T- Square
.
5. It provides an easy means for accurately measuring curved surfaces.
A. Compass
B. Divider
C. Protractor
D. Tape ruler
6. These are used for the purpose of measuring dimensions.
A. Cutting Tools
B. Measuring Tools C. Lining Tools

D. Testing Tools

7. This is used as guide in drawing horizontal lines.
A . Ruler
B. Scale
C. Triangle
D. T- Square
.
8. This instrument is used to draw circles, arcs, radii, and parts of many symbols.
A. Compass
B. Divider
C. Protractor
D. Tape ruler
9. It is a concave, spring-steel blade ranging from 1/4" to 1" wide and 6 to about
300 feet in length
A. Meter stick
B. Tape ruler C. Triangle
D. Ruler
10. It helps a drafter keep the proportions accurate.
A . Ruler
B. Scale
C. Triangle

D. T- Square

Now check your answers using the Answer Key . If you got 90-100% of
the items correctly, proceed to the next Activity.
If not, carefully reviewing the lesson helps you understand the
concepts better. This also helps you learn the skills to mastery level.
Concentrate on the parts that cover the questions you missed. After this, you
are very much ready to proceed to the next learning activity.
MECHANICAL DRAFTING

33


Read the Information Sheet very well then find out how much

you can


Different Measuring Tools/instrument and their application
An understanding of measurement is essential for all parts of manufacturing and
production technology. Measurements must be uniform so that people have common
understanding and application in the production and use of manufactured objects.
Measuring tools are used for the purpose of measuring dimensions, implementing
any work with precision. The measuring tools are also used largely for carrying out different
types of measurements.

Importance of Measuring Tools
Measuring tools are essential for examining a finished product or semi- finished
product. The inspection or examination operations include checking, or testing an object
based on the required dimensions given on a diagram or a sketch. Measurements taken
must be accurate.

MECHANICAL DRAFTING

34

Different Measuring Tools
1. T-Square is used as guide in drawing horizontal lines and in measuring up to 48” straight
line.

T - SQUARE

2.

Triangles are used for drawing vertical and oblique lines. The most commonly used
triangles are the 45 and the 30x 60. Illustrations below show the proper use of
drawing lines and measuring angles using the T-square and triangle.

TRIANGLES
MECHANICAL DRAFTING

35

3. Ruler is the most popular type of measuring tool. It is usually 6 or 12 inches in
length. It is needed for measuring sizes and distances.

RULER
4. Triangular Scale is used in general drawing. Its main purpose is to reproduce
the dimension in full size or to reduce or enlarge them on a drawing. Scales help
a drafter keep the proportions accurate.

TRIANGULAR
SCALE
Steps in Using a Scale
a. Place the edge of the scale parallel to the line being measured.
b. Face the edge of the scale that you're reading toward your non dominant side (if
it's oriented vertically) or away from you (if it's oriented horizontally). This helps
keep you from casting shadows on the relevant face of the scale as you work.
c. Make light marks to indicate the distance you're measuring or drawing out, as
measured by the scale.
d. Adjust dividers with the scale by making a pencil line as long as the dividers
should be wide, using the scale as a guide. Then adjust the dividers by orienting
the points on the ends of the pencil line. Adjusting the dividers by placing the
points directly on the scale might nick the surface of the scale, making it hard to
read.
5. Protractor is used for measuring and setting of angles other than those
obtainable with the triangles.

1
18

0

2
5

PROTRACTOR
MECHANICAL DRAFTING

0

5
0

36



Figure below can be measured and drawn using a protractor

0

80

1
A

9
0

B
STRAIGHT
ANGLE

RIGHT
ANGLE

MOR
E THAN 900
OBTUSE
ANGLE

LESS
THAN 900

0

0

80

ACUTE
ANGLE

1
A

A
00
B

SUPPLEMENT
ARY ANGLES

9
B

COMPLEMENT
ARY ANGLES

KINDS OF ANGLES

6. Tape or tape ruler is a concave, spring-steel blade ranging from 1/4" to 1" wide
and 6 to about 300 feet in length, coiled inside a carrying case. Metric tape ruler
comes in comparable widths and lengths up to 10 meters. It provides an easy
means for accurately measuring curved surfaces.

TAPE OR TAPE RULER

7. Compass is used to draw circles, arcs, radii, and parts of many symbols.

Steps in Using a Compass
MECHANICAL DRAFTING

COMPASS
37

a. Place the point of the drafting compass at the center point of the circle you

intend to draw. If you're drawing an arc, imagine that the arc extends all the
way around into a circle and place the point of the compass at the center of
that imaginary circle.
b. Adjust the leaded end of the compass so that it touches where you'd like the
edge of the arc--or circle--to be. If you're drawing an arc at a specific distance
from the center point, make a line of the desired distance, adjust the point and
leaded end of the compass against the ends of that line, then place the point
of the compass back at the center point of your circle or arc.
c. Grasp the middle of the compass between your thumb and fingers. Twist your
fingers, applying light downward pressure on the compass to mark out the
desired length of arc or circle with the leaded end of the compass.
8. Divider is similar to the compass in construction. As the name implies, divider is
used for dividing distances into a number of equal parts by the trial-and-error
method.

DIVIDERS

Steps in Using a Divider
a. Align each arm of the dividers so that one point is laying on the start point of
the measurement you want to transfer and the other divider point is laying on
the endpoint of that same measurement.
b. Lift the dividers off the measurement you intend to transfer, being careful not
to change their alignment.
c. Place the dividers over the location you'd like to transfer the measurement to,
and make a pencil mark to indicate where each of the dividers' pointers sits.
This duplicates the measurement.

MECHANICAL DRAFTING

38

Self-Check 1.1

Direction: Match Column A with Column B. Write only the letter of the correct answer on
Column A
1.

It is the measuring tool used for measuring and setting of
Angles

Column B
A. Triangle
B. Tape Ruler

2. It is the most popular type of measuring tools, usually 6 or 12
inches in length.

C. Protractor

3. Its main purpose is to reproduce, reduce or enlarge the
dimension of size on a drawing.

D. Scale

4. It is used for drawing vertical and oblique lines.

F. Divider

E. Ruler

5. It provides an easy means for accurately measuring curved
surfaces.


MECHANICAL DRAFTING

39

Directions: Name the different measuring tools shown below. Use a separate sheet for
your answer.

1.______________

3__________
2_________
________
___________

_____

4_________
__________
5
____________________

If all or almost all ( 90-100%) your anwers are correct, that is great.
You may now proceed to the next Activity.
If you got some items wrong, study the lesson again. Carefully
review the lesson to help you understand the concepts better. Concentrate
on the parts that cover the questions you missed. After this proceed to
Activity 1.1.

MECHANICAL DRAFTING

40

It is not enough that you learned concepts on the use of measuring
instruments. Be sure that you are also able to demonstrate the skill on
how to use the measuring instruments. Do this Activity Sheet.

Activity Sheet 1.1

Actual Usage of Measuring Instruments
The activity below is purposely required to test your retention level on the actual
usage of measuring instruments.

Supplies and Materials

Drawing paper

pencil
Tools and Equipment

Measuring Instruments

PROCEDURE:
This is a group activity.
a.
b.
c.
d.

Group yourselves into two.
Assign a leader for each group.
Each group shall be provided with complete measuring instruments
Each group will be given fifteen minutes to demonstrate the uses of
measuring instruments.
e. A leader or any member of the group will explain the functions as well as the
steps in using the tools during the demonstration.
f. Performance of the group may be evaluated through a Demonstration
Checklist provided each member of the group.

MECHANICAL DRAFTING

41

DEMONSTRATION CHECKLIST
Student’s name:
Teacher’s name:
Unit of competency:
Perform Basic Mensuration and Calculation
Competency standards:
Uses of Measuring Instruments
Date of assessment:
Time of assessment:
Instructions for demonstration
Given the necessary materials the student must be able to use the measuring
instruments correctly.
Materials and equipment:
T-square
Triangles
Protractor
Compass and Divider
Tape ruler
Ruler
Other measuring instruments
 to show if a skill is
demonstrated
During the demonstration, the student can:

Yes

No

N/A

Perform this skill without supervision and with initiative
and adaptability to problem situations.







Perform this skill satisfactorily without assistance or
supervision.







Perform this skill satisfactorily but requires some
assistance and/or supervision.







Perform parts of this skill satisfactorily, but requires
considerable assistance and/or supervision.







The student’s demonstration was:
Satisfactory



MECHANICAL DRAFTING

Not Satisfactory



42

How did your group fare? How did you as a member perform? Do you think you
contributed much to the group performance? In what way?

It is not enough that you learned concepts on the use of tools. Be sure
that you are also able to demonstrate the skills on how to use tools. Do
this Operation Sheet.

Operation Sheet 1.1

Drawing of lines, angles and circles
Supplies and Materials

Drawing paper

pencil
Tools and Equipment

Measuring Instruments
Direction: By using the correct measuring tools or instruments, draw the sample figures
below.

PERPENDICULA
R LINES

CONCENTRIC
CIRCLES

MORE THAN
900

OBTUSE ANGLE

ECCENTRIC
CIRCLES

9

LESS THAN 900

0

0

RIGHT ANGLE

ACUTE ANGLE

LINES, ANGLES, AND CIRCLES

MECHANICAL DRAFTING

43

Criteria for Assessment: Analytic Rubrics Scoring
CRITERIA

5 points

3 points

1 point

Accuracy

The output is
accurately done
without any help
from the teacher.

The output is
satisfactorily done
with some guidance
from the teacher.

The output is done
under the
supervision of the
teacher

Layout/Presentation

The output is
properly laid out
and satisfactorily
presented.

The output is
satisfactorily laid out
and presented with
some guidance from
the teacher.

Layout and
presentation fairly
done even with the
guidance of the
teacher.

Speed

The output is done
on or before the
given time.

The output is done
after the allotted
time.

The output is not
thoroughly finished
even after the given
deadline.

Neatness

The output is free
from any erasures.

The output has one
to three erasures.

The output has four
or more erasures.

Rating Scales
POINTS EARNED

NUMERICAL

DESCRIPTIVE

15 – 20

90 – 100

Very Good

10 – 14

86 – 90

Good

5–9

81 - 85

Fair

1–4

75 - 80

Needs Improvement

MECHANICAL DRAFTING

44

LEARNING OUTCOME 2
Clean and store measuring instruments

1. Measuring instruments are cleaned in accordance with established
standards.
2. Measuring instruments are stored in accordance with established
standards.

Materials











T- square
Compass
Drawing paper
Drawing board
Scale
Eraser
Erasing shield
Protractor

MECHANICAL DRAFTING

45

Let us determine how much you already know about use and care of
drafting/measuring tools. Take this test.

Pretest LO 2
A. : Match Column A with Column B. Write only the letter of the correct answer on a
Column A
1
2
3
4
5

A measuring tool used to layout an angle or an arc.
It is the most popular type of measuring tools, usually 6 or
12 inches in length.
Its main purpose is to reproduce, reduce, or enlarge the
dimension or size on a drawing.
It is used for drawing vertical and oblique lines.
It provides an easy means for accurately measuring
curved surfaces

Column B
A.
B.
C.
D.
E.
F.

Triangle
Tape Ruler
T-Square
Scale
Ruler
Protractor

B. List down at least five uses and care of drafting or measuring tools.
1. _______________________________________________________________
_______________________________________________________________
2. _______________________________________________________________
_______________________________________________________________
3. _______________________________________________________________
_______________________________________________________________
4. _______________________________________________________________
_______________________________________________________________
5. _______________________________________________________________
_______________________________________________________________
Now check your answers using the Answer Key. If you got 90-100% of the items
correctly, proceed to the next Learning Outcome.
If not, carefully review the lesson to help you understand the concepts better.
This also helps you learn the skills to mastery level. Concentrate on the parts
that cover the questions you missed. After this, you are very much ready to
proceed to the next learning activity.
MECHANICAL DRAFTING

46

ReadUse Information Sheet veryTools then find out how much you can
the and Care of Measuring well


It is better to own a few good tools than a number of poor ones. In acquiring tools,
be guided by quality and durability. Quality tools are known by their popular trade mark. But
also consider that the life of any drawing or measuring tools will depend on how well you
take care of them. Drafting measuring tools should be well maintained to continue working
properly. Organizing and storing these items have a great deal to do with keeping them in
tiptop shape and good working condition. You can assure that your tools will last long if you
patiently and religiously take care of them.

Good workmanship is associated with the use of quality hand tools. Maintaining
effective use of drafting tools in the production of quality projects is the concern of every
craftsman.
A good tool is a lifelong investment and the craftsman’s best friend. Treat it as such
and you’ll be repaid a thousand times through the results you will obtain from its use.

MECHANICAL DRAFTING

47

Clean/Store Drafting Measuring Tools
1. Be sure to inspect tools before using them. This is to check if they are in working
condition.This can be detected when there is ease and speed when in use.
2. After using a tool, clean it thoroughly with a damp cloth. Wipe it dry with another
piece of cloth before keeping it.
3. When not in use, the T-square is preferably hung by inserting the hole to a nail
(attached to a wall) at the end of its blade.
4. Do not abuse or misuse any piece of drawing instruments.
5. Avoid throwing a tool to anybody; instead, hand it over to him carefully.
6. Avoid setting off the distances individually by moving the scale to a new position from
time to time, because slight errors in the measurements may accumulate and give
rise to a large error.
7. Avoid unnecessary sliding of T-square or triangles protect the drawing. Pick up the
triangle by its tip and tilt the T-square blade upward slightly before moving.
8. Do not pull too much the steel tape of pull-push rule to the coil spring to avoid
damage.
9. Oil the movable parts of the measuring tools such as zigzag rules, calipers, dividers,
and compasses to avoid stock-up.
10. Report defective measuring tools and any hazard to instructor immediately.

MECHANICAL DRAFTING

48

Self-Check 2.1

A. Directions: Write T if the statement is True and F if the statement is False.
Write your answer in your notebook.
_____ 1. Avoid unnecessary sliding of T-square or triangles across the drawing
_____ 2. T-square is preferably hung when not in use.
_____ 3. Report defective measuring tools and any hazard to instructor immediately
_____ 4. After using a tool, clean it thoroughly with a damp cloth.
_____ 5. Be sure to check and then clean tools before and after using them.

B. List down at least five uses and care of drafting or measuring tools.
6. _______________________________________________________________
_______________________________________________________________
7. _______________________________________________________________
_______________________________________________________________
8. _______________________________________________________________
_______________________________________________________________
9. _______________________________________________________________
_______________________________________________________________
10. _______________________________________________________________
_______________________________________________________________

MECHANICAL DRAFTING

49

LEARNING OUTCOME 3
Convert fraction to decimal and vice versa

1. Conversion results of fraction to decimal are accurate up to 2 decimal place.
2. Conversion results of decimal to fraction are accurate to the nearest standard
measurement.

Materials/Resources






Ball pen
Eraser
Drawing paper / Pad paer
Drawing board

MECHANICAL DRAFTING

50

Let us determine how much you already know about the conversion of fraction to
decimal and decimal to fraction. Take this test.

Pretest LO 3

Directions: Convert the following . Write your answers on a separate sheet of paper.
TEST I. - A. Convert fractions into decimals .
1.
2.
3.
4.
5.

¼ to decimal
¾ to decimal
7/16 to decimal
3/8 to decimal
1/8 to decimal

_____________
_____________
_____________
_____________
_____________

B. Convert decimals into fractions .
6.
7.
8.
9.
10.

0.35
0.24
0.75
0.125
0.150

_____________
_____________
_____________
_____________
_____________

TEST II. Round off the following numbers to their nearest hundredths.
11. 76.3456
12. 93.674
13. 27.009
14. 4.6245
15. 5.2532

_____________
_____________
_____________
_____________
_____________

Check if your answers are correct by comparing them with those in the Answer
Key.
If you got 90-100% of the items correct, that means you already familiar with the
lesson covered by Learning Outcome No. 3. However you may still study the
lesson to refresh your memory and learn new concepts.
If you missed a lot of items, do all the activities to gain knowledge and skills
required for mastery.

MECHANICAL DRAFTING

51

Read the Information Sheet very well then find out how much

you can


CONVERSION OF FRACTION AND DECIMAL
Changing Fractions to Decimals

Any rational number can be changed from fractional form to decimal form. This
is done by simply dividing the numerator by the denominator.

Illustrative Examples

A.

4

0.8

5

5)4.0
=

B.

3
4

40

0.75
4)3.00
=

0

28
20
20

4
Therefore,

0

5 equal 0.8
Therefore

3
4

C.

1

0.125

8

equal 0.75

8 ) 1.000
=

8
20

16
MECHANICAL DRAFTING
40

52

40
0

Therefore,

1

Change the fractions to decimals.

A.

1
3

0.333
3)1.000
9
10
9

1

10

3 equal 0.333. . . or 0.3

9
1
The digit 3 is the repeating digit

B.

5

0.8333 . . .

6

6) 5.000
48
20
18

5

20

6 equal 0.8333. . . or 0.83

18
2

Rounding Off Decimals

The digit 3 is the repeating digit.

Metric measurements in decimals are often long numbers. They must often be
rounded to a convenient number of digits. In this text most metric dimensions are either
Sometimes, the that have been rounded off. To help you round off
whole millimeter or two-places decimals repeating digit/digits in the quotients do not
appear at once.
your own calculation, rules of rounding are discussed below.

C.

3

0.428571

MECHANICAL DRAFTING7
7)3.000000
28
20
14

53

1. If the first number to be eliminated is less than 5, simply drop it (and the number to the
right of it) and let the last significant digit stand.
Example:

Round off 25.4 mm to whole millimeter.
Solution: Simply drop the .4
Answer: 25

Example :

Round off 0.3125 (5/16) into two significant digits.
Solution: The first number to be eliminated is 2: Simply drop it and all
numbers to its right(5)
Answer:0.31

2. If the number to be eliminated is 5 or more, drop the number, then add one to the last
digit retained.
Example:
a.

Round off 78.6 into its nearest ones.
Solution: The number to be rounded off is 6 which is greater than 5,
drop 6 and add one to the last digit retained.
Answer: 79

b.

Round off 92.65 into its nearest tenths.
Solution: The number to be rounded off is 5, drop 5 and add one to 6
which is the last digit retained.
Answer: 92.7

MECHANICAL DRAFTING

54

Conversion of Decimals to Fractions
A decimal is changed to a fraction by using 10 or any power of 10 as denominator of the
given decimal. Then change to lowest term when possible.
A.

0.4

=

4

or

10
B.

0.25

=

25

5
or

100
C.

0.328 =

328
1000

2

1
4

or

82
250

or

41
125

Millimeters Equivalent of Decimals and Fractions of an Inch.
Fractions

Decimals

Millimeter

1/16

0.0625

1.588

1/18

0.1250

3.175

3/16

0.1875

4.762

1/4

0.2500

6.350

5/16

0.3125

7.938

3/8

0.3750

9.525

7/16

0.4375

11.112

1/2

0.5000

12.700

9/16

05625

14.288

5/8

0.6250

15.875

11/16

.0.6875

17.462

3/4

0.7500

19.050

13/16

0.8125

20.638

7/8

0.8750

22.225

15/16

0.9375

23.812

1

1.00

25.400

This table is used to find the equivalent decimal numbers and millimeters of a given
fraction
MECHANICAL DRAFTING

55

Self-Check 3.1

Directions:
A. Convert fractions into decimals. Write your answer on a separate sheet of paper.
1.
2.
3.
4.
5.

¼ to decimal
¾ to decimal
7/16 to decimal
3/8 to decimal
1/8 to decimal

_____________
_____________
_____________
_____________
_____________

B. Round off the following numbers to their nearest hundredths.
1. 13.7556
2. 38.614
3. 41.009
4. 8.6245
5. 7.2532

_____________
_____________
_____________
_____________
_____________

C. Convert decimals into fractions . Write your answers on a separate sheet of paper.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.

0.2
0.8
0.84
0.35
0.24
0.75
0.125
0.150
0.65
0.375

_____________
_____________
_____________
_____________
_____________
_____________
_____________
_____________
_____________
_____________


If you got many items wrong, study the lesson again. Carefully reviewing the
lesson helps you understand the concepts better. This also helps you learn the
skills to mastery level. Concentrate on the parts that cover the questions you
missed. After this, you are very much ready to proceed to do activities in
A s s i g n m e n t
S h e e t
N o .
3 . 1 .
MECHANICAL DRAFTING

56

Show that you learned something by doing this activity.

Activity Sheet 3.1

After learning the procedure in converting fraction to decimal;
1. inform your teacher that you are ready to solve problems in converting metric
measurement to decimal and vice versa.
2. convert the following measurements from fractions to decimal.
a) 5/16
b) 1/3
c) 3/16
d) 7/8
e) 5/32
3. When you finish answering, check your work again before submitting it to your
teacher for verification and recording. If your work pass the required output, you are
now ready to proceed to the next activity. If not, make the necessary corrections
then submit your work again.

MECHANICAL DRAFTING

57

LEARNING OUTCOME 4
Convert English to Metric measurement system and vice
versa
and vice versa
1. English to metric equivalent are presented.
2. Conversion of English to metric or metric to English is performed according
to procedure.

Materials/Resources






Ballpen
Drawing paper / Pad paper
Drawing board
Erase

MECHANICAL DRAFTING

58

Let us determine how much you already know about the conversion of metric to
English measurement. Take this test.

Pretest LO 4

A. Direction: Convert the following. Write your answer and solution on a separate
sheet. Round your answers into two decimal places.
1.
2.
3.
4.
5.

25 cm to
63 m to
50 ft to
13 inches
10 mm to

=
=
=
=
=

__________ inches
__________ feet
___________meters
___________ meters
__________ inch

B. Directions: Write the correct measurements as indicated by extension lines below.
Use a separate sheet of paper.
6

8
7

1 INCH

MECHANICAL DRAFTING

59

9
10

1

2 CM

Compare your answers using the Answer Key. If you got 90-100% of the items
correct, that means you are already familiar with the lesson covered by Learning
Outcome No. 4. Therefore you can proceed to the next learning activity . If you
missed a lot of items, do all the activities to gain knowledge and skills required
for mastery

MECHANICAL DRAFTING

60



TRADE MATHEMATICS / MEASUREMENT

Measuring accurately is a skill that should be developed. Inaccurate measurement
would mean waste of time, effort and materials. The development of the skill in measuring
starts with the ability to read measurement
An orthographic or pictorial view of an object cannot be used as a working guide in
the construction of an object without complete and accurate dimensions indicated in the
drawing..

Two systems of measurement
There are two systems of measurement: the English system which originated in
England and the Metric system or Systems International (S.I) which originated in France.

The basic unit in the Systems International measurement is called the meter. The
meter is divided into 100 centimeters. Each centimeter is divided into 10 millimeters. They
are abbreviated as follows:

Millimeters

mm

Centimeters

cm

Decimeters

dm

Meters

m

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61

In the English system , the inch is divided into 16 graduations and the smallest
graduation is read 1/16.

1

3

16

5

16

7

16

1

9

16

11

16

3

16

0

4

15
1
16

16

5

7

1
8

13

3
1

8

8

4

1

1

3

1

1
61 1

6

1

8

8
1 inch

4

2
To read measurement exceeding 1 inch say 2” and for smaller graduations, it is read
and written as: 2” 4/16 or 2 ¼.

1 foot + 2 inches + 3 smaller graduations, it is read and written as:

14” 3/16

In the Systems International measurement , the meter is divided into 10 millimeters.
as shown below:
mm
1 2 3 4 5 6 7 8 9 10

0
Metric System of Measurement

mm
20

mm
30

1

2

3

cm

cm

cm

(linear equivalent)
10 millimeters (mm.) =

1 centimeter (cm.)

10 centimeters (cm.) =

1 decimeter (dm.)

10 decimeter (dm.)

=

1 meter (m.)

10 meters (m.)

=

1 decameter (Dm.)

10 decameter (Dm.) =

1 hectometer (Hm.)

10 hectometer (Hm.) =

1 kilometer (Km.)

10 kilometer (Km.)

1 mayriameter (Mn.)

=

MECHANICAL DRAFTING

62

English System of Measurement
(linear equivalent)
12 inches (in.)

=

1 foot (ft.)

3 feet (ft.)

=

1 yard (yd.)

1 millimeter

=

0.03937 inches (in.)

1 centimeter

=

.3937 inches (in.)

1 meter

=

39.37 inches (in.)

Metric Conversion Table

English Conversion Table
1 inch (in.)

=

.0254 mm.

=

2.54 cm.

=

.0254 (m.)

1 foot (ft.)

=

304.8 mm.

=

30.48 cm

=

.3048 (m.)

1 yard (yd.)

=

914.4 mm

=

91.4 cm

=

.9144 (m.)

Conversion Formulas
Length in inches

x

0.0254

=

length in meters

Length in inches

x

2.54

=

length in centimeters

Length in feet

÷

3.28

=

length in meters

Length in meters

x

39.37

=

length in inches

Length in inches

÷

39.37

=

length in meters

Length in feet

x

0.305

=

length in meters

Length in feet

x

30.5

=

length in centimeters

MECHANICAL DRAFTING

63

Self-Check 1.1

Directions: Write the correct measurements as indicated by extension lines below. Use a
A. English System

MECHANICAL DRAFTING

64

B. Metric System

II. Conversion: Convert the following measurement from metric to English system
or vice versa.

1. 60 cm

=

__________ in.

2. 3 ½ in.

=

__________ cm.

3. 75 cm.

=

__________

4. 10 in.

=

__________ cm.

5.

=

__________ ft.

30 cm

m.


MECHANICAL DRAFTING

65

Congratulations!
lesson. Good luck!

REFERENCES
LO1
Giesecke, Mitchell and Spencer. Technical Drawing; The Macmillan Company:
1999.
French and Vierck. Engineering Drawing 10th edition MacGraw, Hill Book
Company, 1960
German M. Manaois. Drafting 1 and 2 Phoenix Publishing:1983
Norman Stirling. Introduction to Technical Drawing Delmar Publishing: 1977
Competency Based Learning Material, Civil Technology
Competency Based Learning Material, Drafting Technology
http://images.search.yahoo.com/search/image
http://www.ehow.com/how_4880813_use-drafting-tools.html

LO 2
Spence/Atkins. Technical Drafting : Metric Design and Computation, National
Bookstore, Inc.
Competency Based Learning Material, Machine Shop

LO 3
Bookstore, Inc.
LO 4
Bookstore, Inc.

MECHANICAL DRAFTING

66

LESSON 3
Interpret Working Plan and Sketches

LEARNING OUTCOMES:
At the end of this Lesson, you are
expected to do the following:

LO 1. identify assembly and detailed drawing

MECHANICAL DRAFTING

67

Definition of Terms
Axonometric – method of projection in which an object is drawn with its horizontal and
vertical axes to scale but with its curved lines and diagonals distorted
Detailed drawing – drawing of a detail part usually in orthographic projection
Detail dimension – measurements of the detail part or parts of the object
Dimensioning – process of placing measurements in a drawing in the Metric or English
System
Isometric axes – light lines used as bases in constructing an isometric view of an object
Isometric drawing – pictorial drawing showing the three views of the object tilted 30
degrees in front of the observer
Multi-view drawing – drawing that shows more than one view of an object
Notation – all lettering and other dimension found in a drawing or working sketch
Oblique drawing – kind of pictorial drawing of an object one surface of which is shown
parallel to the frontal plane and the other is inclined to it
Orthographic projection – presentation of an object in two or more views by projecting the
outline of the object to the plane of projection perpendicular to each other
Overall dimension – the total width, height and depth of the object
Perspective drawing – a drawing which shows an object as it appears to our eyes
Pictorial view – the presentation of an object where it is viewed showing the three faces of
an object
Working plan – a freehand drawing showing all the information needed to construct an
object

MECHANICAL DRAFTING

68

LEARNING OUTCOME 1
Identify assembly and detailed drawing

1. Orthographic and pictorial drawings are interpreted according to drawing
standard.
2. Assembly and detailed drawing are interpreted according to drawing
standard.

Materials











T- square
Compass
Drawing paper
Drawing board
Scale
Eraser
Erasing shield
Protractor

MECHANICAL DRAFTING

69

Let us determine how much you already know about the assembly and detailed
drawing. Take this test.

Pretest LO 3

A. Directions: Read the statement carefully. Select the correct answer and write the
letter of your answer on a separate sheet of paper.
1. The system for graphically representing an object by line drawing on a flat surface.

A. Orthographic Projection
C. Multi-view Drawing

B. Pictorial Drawing
D. Isometric Drawing

2. Angles of projection generally used for drafting purposes arc.
A. Ninety degrees and Forty Five Degrees
C. Second Angle and Fourth Angle

B. First Angle and Third Angle
D. Thirty Degrees and Sixty
Degrees
3. Standard projection used by many European countries (ISO Standard).
A. Orthographic Projection
C. Isometric Projection

B. Third-angle Projection
D. First-angle Projection

4. The common views used in multi-view drawing are ______________.
A. front, top, and sides
C. front, sides and rear

B. front, rear and sides
D. front, top and rear

5. Type of dimensioning that requires all dimension figures be lettered between guide lines
that are parallel to the bottom edge of the drawing paper.
A. Aligned Method
C. Overall Dimension

B. Location Dimension
D. Uni-directional Method

6. The orthographic view drawn directly above the front view.
A. Auxiliary view
C. Right side view

MECHANICAL DRAFTING

B. Top View
D. Left Side View

70

7. Standard of projection used by Americans, British and Canadians (ANSI Standard).
A. First-angle Projection
C. Diametric Projection

B. Orthographic Projection
D. Third-angle Projection

8. A line used to show the limits of a dimension.
A. Extension line

B. Object line

C. Dimension line

D. Center line

9. An oblique drawing in which the depth axis lines are in full size.
A. Cabinet Oblique

B. Cavalier Oblique

C. General Oblique

D. Oblique Perspective

10. In a scale 1: 20 meters, 5 meters is equivalent to:
A. 20 cm.

B. 15 cm.

C. 5 cm.

D. 10 cm.

11. This is the type of oblique pictorial view where the dimension of the receding features of
the object is drawn half-scale.
A. Cabinet Projection
C. Isometric Projection

B. Cavalier Projection
D. Orthographic Projection

12. The point where the horizontal line in the perspective view seems to converge or meet.
A. Station Point

B. Vanishing Point

C. Center Point

D. Piercing Point

13. Type of dimensioning that requires all dimension figures, except to angular contours, be
lettered between guide lines that are parallel to the dimension lines.
A. Aligned Method


14. The process of describing the object by placing sizes and related information on a
drawing.
A. Dimensioning
B. Scaling

B. Sectioning
D. Tolerancing

15. This is the dimension that gives the detail and overall sizes of the object.
A. Location dimension
C. Shape dimension

B. Figure Dimension
D. Size Dimension

B. Directions: Write the names of the kind of lines indicated by numbers 1 to 10. Place
your answer on a separate sheet of paper.

MECHANICAL DRAFTING

71

C. Directions: Base on your answer on the drawing above, write the name of the view
where you find the different kind of lines listed below.

Kind of Lines
1.
2.
3.
4.
5.

Center line
Long-break line
Cutting-plane line
Leader line
Section line

Name of Views
-

Right-side view
Front view
Top view
Top view
Front view

Compare your answers using the Answer Key. If you got 90-100% of the
items correct, that means you are already familiar with the lesson covered by
Learning Outcome No. 1. Therefore you can proceed to the next learning activity .
If you missed a lot of items, do all the activities again to gain knowledge and skills
required for mastery.

MECHANICAL DRAFTING

72


A drawing is made up of different lines. Each line represents something. A surface,
a hidden surface, an extension of a surface, a center of a hole, or a line with dimension on it.
In order to make the drawing easier to read and understand, each kind of line is drawn with a
different line weights. Read and understand the following.

ALPHABET OF LINES
Visible line – a thick line that represents the visible edges or outline of the object; also
known as the object line
Hidden line – a medium thick line composed of short dashes about 2-3 millimeters long with
space between dashes about 1-2 millimeters wide; itt represents the surface or edges that
cannot be seen
Center line – a thin line consisting of two long dashes and short dash drawn alternately with
a gap of at least 2 millimeters in between; it represents the axis or center of symmetrical
shapes like a ball, washer, rectangular block, cube
Section line – a thin lines to show the surface that has been cut; they are spaced evenly at
45 degrees with the horizontal to make shaded effect
Extension line – a thin line that extends from the object in order to show dimension limits
Dimension line – a thin line with an arrowhead in one end used to indicate the
measurements of the object
Long-break line – a medium thick line consisting of broken and straight lines drawn
alternately. This is also known as the limiting line. This limits the length of an elongated
object without changing the size of its view.
Short-break line – thick line drawn in freehand to show details that a part has been cut off
or broken out.

MECHANICAL DRAFTING

73

Leader line – a short inclined thin line with an arrowhead at the end and short horizontal line
on the other end.
Phantom line – a thin line that shows position(s) of part of an object that moves drawn by
two short dashes and one long dash.
Cutting-plane line –thick lines used to indicate an imaginary cut through an object along the
line. Made up of two long dashes broken in one end with an arrowhead and two short
dashes drawn in between the long dashes.

MECHANICAL DRAFTING

74

Self-Check 1.1

Directions: Read and interpret the given figure below. Identify the lettered lines used
(A – N) to draw the object. Place your answer on a separate sheet of paper.

A.
B.
C.
D.
E.
F.
G.

________________________
________________________
________________________
________________________
________________________
________________________
________________________

H.
I.
J.
K.
L.
M.
N.

_________________________
_________________________
_________________________
_________________________
_________________________
_________________________
_________________________


MECHANICAL DRAFTING

75

Show that you learned something by doing this activity

Activity Sheet 1.1
Directions: Sketch the line being referred to in the Table below. Place your answer
on a separate sheet of paper.

Kind of Lines

Sketch of the Lines

Short-break line

Center line

Extension line
Dimension line
Leader line

Phantom line

Section line

Hidden line

Long-break line

Cutting-plane line or
Viewing-plane line

Visible line

MECHANICAL DRAFTING

76

Criteria for Assessment:

Analytic Scoring Rubrics

Criteria

5 points

3 points

1 point

Accuracy

All lines are drawn
appropriately
according to its
characteristics

There are 1 to 3 lines
inappropriately
drawn according to
its characteristics

Majority of the lines
are inappropriately
drawn

Neatness

Finished output
was neatly done,
pleasing, and no
erasures/smudges

Time Management

Finished the task 5
minutes before the
given time

Pleasing but
erasures and
smudges are
observable on the
finished output
Finished the task on
time

Finished output
have so many
erasures and
smudges
Unable to finished
the given task

Rating Scale:

Points Earned

Numerical

Descriptive

12 - 15

91 - 100

Very Good

8 - 11

86 - 90

Good

4-7

81 - 85

Fair

1- 3

75 - 80

Needs Improvement

Remarks:
_____________________________________________________________________
_____________________________________________________________________

MECHANICAL DRAFTING

77


Artist’s drawing is generally called freehand drawing that is, drawings are made
without the use of drawing instruments or straightedges. Freehand drawing is synonymous
to sketching. This technique is necessary in any area of drafting and an important skills for
everyone. Skills in freehand drawing can be achieved through constant training and correct
practice.

Line Sketching
One advantage of freehand sketching is that it needs only patience and continuous correct
practice.
Basic Line Sketching
Kind of lines

For right-handed

Direction of strokes

Strokes are drawn from left to right for
right-handed
and

For left-handed

from right to left for left-handed
individuals.

Horizontal lines

Strokes are drawn downward.
Vertical lines
MECHANICAL DRAFTING

78

Inclined to the right
Inclined strokes (diagonal) are drawn
downward

Inclined to the left

Curved strokes are drawn downward for
either right-handed or left-handed

Curved line

MECHANICAL DRAFTING

79

Self-Check 1.2

Directions: Using a separate sheet of paper, sketch the following lines indicated in
each box.
Lines should be drawn freehand.

Horizontal line
Vertical line

Inclined to the left

MECHANICAL DRAFTING

Inclined to the right

80

Curved to the left

Curved to the right


MECHANICAL DRAFTING

81

Operation Sheet 1.2

Directions: Below is a suggested activity on line exercises. Choose at least twelve
(12) from the given examples on line sketching. Observe accuracy. Place your drawings in

LINE EXERCISES

MECHANICAL DRAFTING

82

Find out by accomplishing the Scoring Rubrics honestly and sincerely.


Criteria

5 points

3 points

1 point

Accuracy

All lines are drawn
appropriately and
freehand

Neatness

Finished output
was neatly done,
pleasing, and no
erasures/smudges

Time Management

Finished the task
10 minutes before
the given time

Some lines are
drawn
inappropriately and
NOT in freehand
Pleasing but
erasures and
smudges are
observable on the
finished output
time

Most of the lines are
inappropriately
drawn and NOT in
freehand
Finished output
have so many
erasures and
smudges and quite
unpleasant
Unable to finished
the given task

Rating Scale:

Points Earned
12 - 15
8 - 11
4-7
1- 3

Numerical
91 - 100
86 - 90
81 - 85
75 - 80

MECHANICAL DRAFTING

Descriptive
Very Good
Good
Fair
Needs Improvement

83

Remarks:
______________________________________________________________________
______________________________________________________________________
_____________________________________________________________________
______________________________________________________________________
______________________________________________________________________

How did you find this activity? Did you enjoy answering it? Is
it hard? Challenge yourself by keep on trying to finish this activity.
Be patient. Have self confident.

MECHANICAL DRAFTING

84



THEORIES AND PRINCIPLES OF ORTHOGRAPHIC PROJECTION
Multi-view drawing – a drawing that shows more than one view of an object.
Orthographic Projection – A system for graphical representation of an object by a
line drawing on a flat surface.
Orthographic View – a drawing that shows a side of an object viewed directly from
90 degrees.
Six (6) Principal Views of an Object:
The simple work piece below shows the six (6) principal sides or views.

TOP
VIEW

REA
R VIEW

L
SIDE VIEW

FRO
NT VIEW

R
SIDE VIEW
BOTTO
M VIEW

MECHANICAL DRAFTING

85

An orthographic view is made by projecting the edge of the object perpendicular to a
plane of projection.

Planes of Projection
Three planes of projection are used in orthographic drawing. These are called
the horizontal plane, frontal plane, and the profile plane.

The planes of projection join and form quadrants. The quadrants are called first
angle, second angle, third angle, and fourth angle. The first and the third quadrants are
used for drafting purposes.
MECHANICAL DRAFTING

86

Overall Size of the Object
1. Height is the perpendicular distance between two horizontal planes.

HEIGHT

WIDTH

2. Width is the perpendicular distance between two profile planes.
3. Depth is the perpendicular distance between two frontal planes.

DEPTH
MECHANICAL DRAFTING

87

Self-Check 1.3


Directions: Supply the correct information on each blank.
1.

The a system of orthographic projection that places the object on the first quadrant is
called __________________.

2.

Located below the top view is the _______________ of the Third angle projection.

3.

The a system of orthographic projection that places the object on the third quadrant
is called ______________.

4.

Located below the first is the ______________ of the first-angle projection.

5.

The perpendicular distance between horizontal planes is referred to as
______________.

6.

The perpendicular distance between profile planes is called ______________.

7.

The perpendicular distance between frontal planes is called ______________.

MECHANICAL DRAFTING

88



Mechanical drawing is describing the shapes of objects completely and exactly by
the use of orthographic views. Although there are six principal views that can be drawn in an
object, only the three regular views are normally required in the preparation of a working
plan.

ORTHOGRAPHIC PROJECTIONS
1. First-Angle Projection (ISO Standard)
The first-angle projection is a system of orthographic projection used by the
European countries which places the object on the first quadrants.

Here the horizontal plane is below the object.



The top of the object is projected down the horizontal plane.
The rear projects to the frontal plane.

MECHANICAL DRAFTING

89

Unfolded Planes
With the planes unfolded and laid flat, the front view is above the top view.

The position of the unfolded planes in the first-angle
projection

SYMBOL USED FOR FIRST ANGLE
PROJECTION
2. Third-angle Projection (ANSI)
The third-angle projection is a system used in the United States which places the
object in the third quadrants.

MECHANICAL DRAFTING

90

The third-angle projection places the object in the third quadrant. (An observer here
would be facing the frontal plane).


Observe that the object is placed below the horizontal plane.



The top view of the object projects up to it, therefore, the top view is in the
horizontal plane.



The object is behind the frontal plane. The front view of the object projects
forward to it, therefore, the view is on the frontal plane.



The side of the object projects to the profile plane, therefore, the side view will be
seen in the profile plane.

Unfolded Planes
If the planes be unfolded and laid flat, the top view would be above the front view.

The position of the unfolded planes in the third-angle projection

SYMBOL USED FOR THIRD ANGLE
PROJECTION
MECHANICAL DRAFTING

91

Self-Check 1.4

Direction: You have just finished the study of the basic principles of orthographic
projection. To ensure understanding, try your best to supply the needed
information to complete the following statements.

1. The system for graphically representing the object by a line drawing on a flat surface is
called __________________.

When the three planes of projections joined together, they will form quadrants. They are
the following: (in any order)
2.
3.
4.
5.

____________________
____________________
____________________
____________________

The quadrants used for drafting purposes are (in any order)

6.
7.

____________________ and
____________________

Orthographic view is drawn by projecting the edge of the object perpendicular to these
planes of projection.
8. ____________________
9. ____________________
10. ____________________


MECHANICAL DRAFTING

92


Activity Sheet 1.4

Directions: Below (Fig. 1) is a simple activity for you to work on. Sketch the three regular
views using the Third-angle projection. Practice the task following the given procedure
Tools and materials:




Drawing paper or a long bond paper
Pencil
Eraser

Equipment:



Procedure:
1. Prepare all the tools and materials needed.
2. Study the given object (Figure 1) carefully. Observe its dimensions: width, height and
depth.
3. Sketch two parallel vertical projection lines representing the width of the object.
4. Draw two parallel horizontal lines projection representing the height of the object.
5. To locate the top view, measure the depth of the top then draw two horizontal parallel
lines representing the top view, or if you prefer to locate the right-side view, measure
the depth of the right-side then draw two parallel vertical lines representing the rightside view. To transfer the depth of the top view to the right-side view or vice versa,
please refer to the accepted methods shown below.

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93

4
50

R
R

1

2

Two accepted methods used to transfer the depth of the top view to the side view.
6.

Complete the drawing by applying all appropriate lines to make the object visible.

7.

Erase unnecessary lines then double check your drawing.

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PICTORIAL DRAWING
A pictorial drawing shows likeness (shape) of an object as viewed by the observer. It
represents a portion of the object and shows the method of its construction. In some
presentations, the whole object is shown in one view.

Types of Pictorial Drawing:
A. Axonometric Pictorial Drawing
1. Isometric drawing – a pictorial drawing showing the three surfaces of the object
tilted 30 degrees in front of the observer.
Angle

a = 300, s =

Width:

Scale 1:1

30

Height: Scale 1:1
Depth:

Scale 1:1

Isometric drawing according to standard
2. Dimetric drawing – the angle that is used for the horizontal planes varies according
to the angle of view that has been chosen. This type is not widely used.
3. Trimetric drawing - a classification of an axonometric projection where in a cube is
positioned in the way that no axes and angles are equal when projected to the plane
projection.

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95

B. Oblique Pictorial Drawing
1.

Cavalier drawing – an oblique drawing in which the depth axis lines are full
scale or in full size.

2.

Cabinet oblique – depth axis lines are drawn one-half scale.

3.

General oblique – depth axis lines vary from one-half to full size.

CAV
ALIER

CA
BINET

GENERAL

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C. Perspective Pictorial Drawing
1. 1-pt. or Parallel perspective – a perspective drawing using one vanishing
point, the front view is drawn in its true shape in full or scale size.

2. 2-pt. or Angular perspective – a perspective drawing using having two vanishing
points.

ANGULAR ( TWO-POINT )

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3. 3-pt. or Oblique perspective – a perspective drawing using three vanishing points.

MECHANICAL DRAFTING

98

.

Self-Check 1.5

Instructions: Supply the needed information to complete the following statements.

1. A drawing showing more than one side of an object tilted in front of the observer.
a. pictorial drawing

b. artistic drawing

c. multi-view drawing d. orthographic drawing

2. The place or point where the observer is supposed to stand while viewing the object.
a. vanishing point

b. center point

c. piercing point

d. station point

3. The point where the horizontal line in the perspective view seems to converge or meet.
a. station point

b. vanishing point

c. center point

d. piercing point

4. The object is placed on the horizon at the eye-level of the observer.
a. bird’s eye view

b. worm’s eye view c. man’s-eye view

d. orthographic view

5. An oblique drawing in which the depth axis lines are in full size.
a. cabinet oblique

b. cavalier oblique

c. general oblique

d. oblique perspective

6. Iso means equal, metric means _____________.
7. Circle becomes ellipse in ________________.
8. Lines that are not parallel to the three base lines in isometric are called ____________.

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Isometric Drawing

Vertical
axis

3
0

0

3
0

0

Right – cross axis

Left-cross axis
Axes used in Isometric Drawing
1. Vertical axis
2. Right-cross axis
3. Left-cross axis
MECHANICAL DRAFTING

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Isometric drawing – a pictorial drawing showing the three surfaces of the object tilted
30 degrees in front of the observer.
Isometric lines – are lines drawn parallel to the isometric axes.
Steps in Drawing Isometric from a given Orthographic Views
1. Study the given orthographic views carefully. Estimate the width, height and the
depth of the object, then sketch the axes used in isometric drawing.

2. Transfer the height (A), the width (B), and the depth (C) of the object to the
corresponding axis respectively.

Height (A)

Width (B)

Depth (C)

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101

3.Sketch isometric lines to complete the isometric box.

ISOMETRIC BOX
4. Layout details of the object inside the box then finish the pictorial view by drawing
the object lines.

Isometric view

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Activity Sheet 1.5

Directions: Below is a simple activity for you to work on. Sketch the isometric pictorial of
the given orthographic views. Practice the task following the given procedure.
 Drawing paper or a long bond paper
 Pencil
 Eraser
Equipment:
 Drawing Table (Drafting Table or Drawing Board)
Procedure
1. Study the given orthographic views carefully. Estimate the width, height and the
depth of the object, then sketch the axes used in isometric drawing.
2. Transfer the height (A), the width (B), and the depth (C) of the object to the
corresponding axis respectively.
3. Sketch isometric lines to complete the isometric box.
4. Layout details of the object inside the box then finish the pictorial view by drawing the
object lines.
5. Double check your drawing then erase unnecessary lines.
Sample orthographic
views
2

1

4

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Find out
by accomplishing the Scoring Rubric honestly and sincerely.

Analytic Rubrics Scoring

Criteria

5 points

Accuracy

The isometric
pictorial view was
drawn according to
standard

Neatness

Time Management

3 points

1 point

The isometric
pictorial view was
somehow drawn
according to
standard
Finished output was Pleasing but
neatly done,
erasures and
pleasing, and no
smudges are
erasures/smudges
observable on the
finished output
Finished the task
10 minutes before
time
the given time

The isometric
pictorial view was
drawn NOT
according to
standard
Finished output
have so many
erasures and
smudges and quite
unpleasant
Unable to finished
the given task

Rating Scales:

Points Earned
12 - 15
8 - 11
4-7
1- 3

Numerical

Descriptive
91 - 100
86 - 90
81 - 85
75 - 80

Very Good
Good
Fair
Needs
Improvement

Remarks:
_____________________________________________________________________
______________________________________________________________________

MECHANICAL DRAFTING

104

AsaSAsddasaSfffKnowKnow?


More information on Oblique Drawing
Oblique drawing – the kind of pictorial drawing of an object one surface of which is shown
parallel to the frontal plane and the other is inclined to it.

Axes in Oblique Drawing

Variations in Direction of Receding

Axis

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105

Classifications of Oblique Pictorial Drawing
1. Cavalier drawing – An oblique drawing in which the depth axis lines are full
scale or in full size. The receding lines are true depth – that is makes an angle
of
45 degrees and 30 degrees with the plane of projection.

2.
Cabinet oblique – Depth axis lines are drawn one-half scale. When the
receding line is drawn to half – size, and the projectors makes an angle of 30, 45, 60
degrees respectively.

3.
General oblique – Depth axis lines vary from one-half to full size. Drawn at
any convenient angle and the receding lines are drawn to full size, onethird size, one-half size, or one fourth-size.

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106

Procedure in Sketching Oblique Pictorial View

1. Study carefully the given orthographic views. Sketch the vertical line OB and horizontal
line OA.

B

O

A

2. Draw line OC as the receding line.
B
C

O

A

3. Complete the oblique box by sketching parallel lines to the oblique axes.

B
C
4
0

5

O

A

4. Layout the details of the object inside the oblique box.

MECHANICAL DRAFTING

107

5.

Erase the unnecessary lines to complete the drawing.

CAVALIER OBLIQUE

MECHANICAL DRAFTING

CABINET OBLIQUE

108

Self-Check 1.6

Instructions: You have just finished the study of the basic principles of oblique drawing.
To ensure understanding, try your best to supply the needed information to
complete the following statements.
__________ 1. A drawing that shows a front view in its true relations and dimensions just as
it would be in working drawing.
a. Isometric drawing
c. Orthographic drawing

b. Oblique drawing
d. Perspective drawing

__________ 2. This type of oblique pictorial view where you can see the exact dimension of
the object.
a. Cabinet projection
c. Isometric projection

b. Cavalier projection
d. Orthographic projection

__________ 3. The receding lines in oblique pictorial drawing regularly used
a. 30 degrees
c. 60 degrees

b. 45 degrees
d. 75 degrees

__________ 4. This is the type of oblique pictorial view where the dimension of the receding
features of the object is drawn half-scale.
a. Cabinet projection
c. Isometric projection

b. Cavalier projection
d. Orthographic projection

__________ 5. Give at least three rules to be followed in sketching oblique views.
5.1 ________________________________________________________
________________________________________________________
5.2 ________________________________________________________
________________________________________________________
5.3 ________________________________________________________
________________________________________________________

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Activity Sheet 1.6

Directions: Below is a simple activity for you to work on. Sketch the oblique pictorial of the
given orthographic views. Practice the task following the given procedure.

Drawing paper or a long bond paper

Pencil

Eraser
Equipment:



Procedure
1. Study carefully the given orthographic views. Sketch the vertical line and horizontal line
that will serve as your axes.
2. Draw the receding line.
3. Complete the oblique box by sketching parallel lines to the oblique axes.
4. Layout details of the object inside the box then finish the pictorial view by drawing the
object lines.
5. Double check your drawing then erase unnecessary lines.

Sample orthographic views

MECHANICAL DRAFTING

110




Criteria

5 points

3 points

Accuracy

The pictorial view
was drawn
appropriately in
freehand

The pictorial view
was somehow drawn
inappropriately and
NOT in freehand

Neatness

Time Management

Finished output
was neatly done,
pleasing, and no
erasures/smudges

Finished the task
10 minutes before
the given time

1 point

Pleasing but
erasures and
smudges are
observable on the
finished output
time

The pictorial view
was inappropriately
drawn and NOT in
freehand
Finished output
have so many
erasures and
smudges and quite
unpleasant
Unable to finished
the given task

Rating Scale:

Points Earned
12 - 15
8 - 11
4-7
1- 3

Numerical

Descriptive
91 - 100
86 - 90
81 - 85
75 - 80

Very Good
Good
Fair
Needs
Improvement

Remarks:

MECHANICAL DRAFTING

111



SCALING
Proportion – a size or distance in comparison to another.
Proportion Scale – a scale for measuring distances for drawings. Marks on a proportion
scale indicate the reduced size in proportion to the full or actual scale.
Scale – a graduated measurement to allow production of a drawing to any size desired.

The Scale
To draw accurate drawings, you must measure accurately, develop the ability to
measure distances. The measuring tool, called the scale (commonly known as the metric
scale), has several edges. Each edge is called the proportion scale. It helps the drafter to
reduce or enlarge the drawing of an object in proportion to its actual size.
Function of a Scale
1. To measure or layout line distances accurately either in full size and larger or smaller
than full size.
2. To produce drawing to a certain sizes (making drawing into scale)
The Scale Ratio (Object/Drawing)
Scale ratio 1 : 1 – means that 1 mm. on the drawing represent 1 mm. on the actual
product or work piece.

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112

Each mark as you pass represents one millimeter from zero.

Proportion Scales
Most drafting scales are equipped with proportion scales. Each of these scales aids
the drafter in reducing an object on a drawing in a different proportion.

Commonly Used Scale
Full-Size Scale – has a ratio of 1:1. This means that 1 mm on the drawing
represents 1 mm of the actual object. The views on the drawing paper are the same size as
those of the actual object.

Reduced Scale (Scaled-down) – has a ratio of 1:2. This means that 1 mm on the
drawing represent 2 mm on the actual object. The views of the actual object are twice the
size of the views on the drawing paper.

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113

Sometimes you want to show the shapes of the objects clearly and to be able to
show the dimension more convenient, you have to prepare drawings that are larger than the
actual object. Listed below are sample of enlarged scale.

Enlarged Scale (Scaled-up)
Scale 2:1 - This means that every 2 mm on the drawing represent 1 mm on the
actual object. The views on the drawing paper are twice the size of those of the actual
object.
Scale 5:1 - This means that every 5 mm on the drawing represent 1mm on the
actual object. The views on the drawing paper are five times larger than those of the
actual object.

Things to Remember in Scaling a Drawing
1. Whenever possible, the work piece must be drawn into full-size.
2. When dimensioning, always enter the actual dimension of the work piece.
3. Angular dimensions remain the same regardless of the scale to which an object is
drawn.
4. The first figure of a scale designation refers to the dimension used to construct the
views. The second figure of a scale designation refers to the actual dimensions of
the object being drawn.

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114

Self-Check 1.8
Directions : You have just finished the study of the basic principles of scaling. To
ensure understanding, try your best to interpret the following scale designations.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.

3:1
10:1
1:15
1:1
1: 20
50:1
1:75
100:1
1:200
500:1


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Dimensioning
Dimensioning – placing sizes and related information on a drawing
Size dimension – gives the detail and overall sizes of the object
Location dimension – merely locates part or parts and features of the object

Dimensioning Method
Aligned Method
All dimensions are placed aligned with the dimension line and be read from
either the bottom or right side of the paper.

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116

Unidirectional Method
In the unidirectional method, all dimensions are read from the bottom of the
page as illustrated. This is a new method.

Kinds of Dimensions
Over-all dimension – every object, regardless of its shape, has three over-all dimensions.
An over-all dimension indicates the over-all width, height and depth of an object.

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117

Detail dimensions – provide size or location information concerning any feature or
details of an
object other than its over-all dimension.

Rules in Dimensioning
For a beginner like you, remember these dimensioning rules when placing measurements in
your drawing.
1. Dimensions should be placed between the views.
2. Avoid repetition of dimensions.
3. Use outside dimension if the space is limited, and use an inside dimension if there is
enough space.
4. Continuous dimensions should be used whenever possible.
5. Staggered dimensioning should be used when the space for dimensioning is limited.
6. When dimensioning a circle, it should be from center to center.
7. Dimensions are entered in millimeters without measures.
8. Extension lines must have a distance of about 10 mm from the object edge and an
approximate 2 millimeters after the dimension lines.

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118

Self-Check 1.9

Directions: You have just finished the study of the basic principles in dimensioning. To
ensure understanding, try your best to supply the needed information to
complete the following statements.
__________ 1. This is the dimension that gives the detail and overall sizes of the object.
A. Location Dimension
B. figure dimension
C. Shape Dimension
D. size dimension
__________ 2. This kind of dimension merely locates part or parts of the object.
A. Location Dimension
B. Figure Dimension
C. Shape Dimension
D. Size Dimension
__________ 3. This dimension represents the total width, height and depth of an object.
A Detail Dimension
b. Location Dimension
C. Overall dimension
d. Size Dimension
__________ 4. The process of describing the object by placing sizes and related
information on a drawing.
A. Dimensioning
B. Sectioning
C. Scaling
D. Tolerancing
_________ 5. Type of dimensioning that requires all dimension figures, except to angular
contours, be lettered between guide lines that are parallel to the dimension
lines.
A. Aligned Method
C Overall Dimension
D. Uni-Directional Method
__________ 6. This dimension represents the width, height and the depth of each part
of the same object.
A. Detail Dimension
D. Size Dimension
__________ 7. Type of dimensioning that requires all dimension figures be lettered
between guide lines that are parallel to the bottom edge of the drawing
paper.
A. Aligned Method


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119


Operation Sheet 1.9
Directions: Below is a simple activity for you to work on. Sketch the orthographic views of
the given object. Practice the task following the given procedure.
Provide the appropriate dimensions in each view

 Drawing paper or a long bond paper
 Pencil
 Eraser
Equipment:
 Drawing Table (Drafting Table or Drawing Board)
Procedure:
1. Study the given object below carefully.
2. Sketch the regular views of the given object then provide dimensions in each
views using the Aligned Method of dimensioning.
3. Observe strictly the following dimensioning rules:
a.
b.
c.
d.
e.

f.
g.

Dimensions should be placed between the views.
Avoid repetition of dimensions.
Use outside dimension if the space is limited, and use an inside dimension if
there is enough space.
Continuous dimensions should be used whenever possible.
Staggered dimensioning should be used when the space for dimensioning is
limited.

Dimensions are entered in millimeters without measures.
Extension lines must have a distance of about 10 mm from the object
edge and an approximate 2 millimeters after the dimension lines.

(Figure 1)
MECHANICAL DRAFTING

120

Note: Do not include the two (2) holes in your orthographic views.

( Figure 2)

MECHANICAL DRAFTING

121



Criteria
Accuracy

Neatness

Time
Management


5 points
Measureme
nts supplied in each
views were based
on the given rules

Finished
output was neatly
done, pleasing, and
no
erasures/smudges
Finished the
task 10 minutes
before the given
time

3 points

1 point

There were
some measurements
that did not comply
with the given rules

Pleasing but
erasures and
smudges are
observable on the
finished output
Finished the
task on time

Most of the
supplied
measurements does
not comply with the
given rules
Finished
output have so
many erasures and
smudges and quite
unpleasant
Unable to
finished the given
task

Rating Scale:

Points Earned

Numerical

Descriptive

12 - 15

91 - 100

Very Good

8 - 11

86 - 90

Good

4-7

81 - 85

Fair

1- 3

75 - 80

Needs Improvement

Remarks:
MECHANICAL DRAFTING

122



Preparation of Working Plans
Assembly Working Plans
An assembly working plan is one that indicates how the individual parts of a machine
or products are assembled to make a complete unit. An assembly working plan serves the
following purpose:

1. It describes the shape of the assembled unit or product.
2. It shows how the parts of the assembled unit are positioned in relation to each
other.
3. It identifies each component that forms part of the assembled product.
4. It provides parts list that describes and essential data concerning each part of the
assembled unit or product.
5. It provides, when necessary, reference information concerning the physical or
functional characteristics of the assembled unit.

Sample Assembly Working Drawing
MECHANICAL DRAFTING

123

Detail Working Plans
A technical working plan of a single part of a machine or mechanism gives enough
information to allow the part to be made. It describes the shape and indicates the
dimensions of the object.

Sample Detail Working Drawing
Parts List
A parts list is a list of all parts required to put an assembly together. This list itemizes
important data about each part of an assembled machine or product such as part name,
material, quantity required, and size specifications.
Sample figure below shows a simple parts list along with suggested dimensions. In
the material column STD abbreviation represents for all standard parts. This means that
they must be purchased. Complete specifications for standard parts must always be listed in
the name column together with the part name.
Only the names of non-standard parts are listed in the name column The material
from which the standard parts are made is listed by abbreviations in the material column
such as C.I., H.R.S., C.R.S., Alum.
The upper or lower right-hand corner of an assembly working plan is usually
reserved for the parts list.

MECHANICAL DRAFTING

124

MECHANICAL DRAFTING

125

Self-Check 1.10

Directions : You have just finished the study of the basic principles in assembly and
detail working plans. To ensure understanding, carefully study the
given samples below and complete the table for the parts list.

Figure 3 ) Vee Block

MECHANICAL DRAFTING

126

Vee Block

Part

Name

Quantity

Material


MECHANICAL DRAFTING

127


Operation Sheet 1.10

Directions: You have just finished the study of the basic principles in assembly and detail
working plans. To ensure deeper understanding on reading and interpreting
working plans, do the given sample tasks below and by completing the table for
the parts list. (Figures 4 and 5)

MECHANICAL DRAFTING

128

(Figure 4) Special Flaring Tool

Part

Name

Quantity

Material

Directions: Provide the complete parts list of the Toolmaker’s Vise on the table below.
(Figure 5) Toolmaker’s Vise

MECHANICAL DRAFTING

129

Part

Name

Quantity

Material

Congratulations!
lesson. Good luck!

REFERENCES
LO1
Giesecke, Mitchell and Spencer, Technical Drawing; The Macmillan
Company: 1999
Nelson, John, How to Read and Understand Blueprints, Van Nostrand
Reinhold Company, 1982
Manaois, German, Drafting 1 and 2; Phoenix Publishing: 1983
Esguerra and Molino, Exploratory Drafting; Abiva Publishing: 1980
Walker, John, Exploring Drafting Basic fundamentals, The Goodheart-Willcox
Co., Inc, 1975

Stirling, Norman, Introduction to Technical Drawing, Metric Edition
MECHANICAL DRAFTING

130

.

LESSON 4
LESSO
Apply Safety Practices
N4

LEARNING OUTCOMES:
do the following:

LO 1. identify hazardous area;
LO 2. use personal protective clothing and devices

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131

Definition of Terms
Ergonomic principles - a principle of handling a delicate object or task.
First aid - it implies includes all forms of remedies given immediately to
humans in order to minimize or prevent casualties or fatalities caused by
accidents or normal course of time.
Hazard - particular place, thing, or situation that is a risk or danger to the
person involved.
Health – overall condition of the body
Injury - damage or harm caused to the structure or function of the body caused
by an outside agent or force, which may be physical or chemical.
Quality standards - set of exact specifications to become patterns of actions.
Sanitize - maintain high standard of housekeeping.
Self-Discipline - refers to doing things spontaneously without being told or
ordered.
Standard - any established measure; an accurate type; an authoritative model
as an example or comparison.
Symbols - generally common illustrations printed on the signs which
sometimes carry a descriptive word or few words.
Waste disposal - proper discharge of any solid waste into or in any hand
Workplace - office, premises or worksite where a worker is temporary or
habitually assigned.

Acronyms
OHSC – Occupational Health and Safety Commission
OHSS - Occupational Health and Safety Standards
PPE - Personal Protective Equipment actions.

MECHANICAL DRAFTING

132

LEARNING OUTCOME 1
Identifying Hazardous Area

PERFORMANCE
STANDARDS
1. Hazards are identified correctly in accordance with OHS procedures.
2. Safety signs and symbols are identified and adhered to in accordance with
workplace safety procedure.

Materials
a. Drawing paper
b. Pencil
c. Any coloring medium

MECHANICAL DRAFTING

133

Let us determine how much you already know about the identifying hazardous
area. Take this test.

Pretest LO 1
A. Multiple Choice. Write the letter of the correct answer.
_____ 1. It will be used only to warn or caution against practices.
A. Caution sign

B. Danger sign

C. Exit sign

D. Safety sign

_____ 2. This preventive sign shall be used only where an immediate hazard exists.
A. Caution sign

B. Danger sign

C. Exit sign

D. Safety sign

_____ 3. This is a cross-disciplinary area concerned with protecting the safety, health and
welfare of people engaged in work or employment.
A. Occupational Safety and Health
B. Department of Labor and Employment

C. Occupational Labor Code
D. Department of Trade and
Industry
_____ 4. Occupational safety and health requirements may be reinforced in civil law and/or
criminal law.
A. Economic

B. Labor

C. Legal

D. Moral

.
_____ 5. Take out unnecessary items and dispose.
A . Seiri

B. Seiketsu

C. Seiso

D. Shitsuke.

_____ 6. Arrange necessary items in good order for use.
a . Seiri
B. Seiketsu
C. Seiso
.
_____ 7. Do things spontaneously without being told or ordered.
A . Seiri

B. Seiketsu

C. Seiso

D. Seiton

D. Shitsuke.

_____ 8. This type of hazards are solid, liquid, vapor or gaseous substances, dust, fume or
mist.
A . Biological

B. Chemical

MECHANICAL DRAFTING

C. Ergonomic

D. Safety
134

.
_____ 9. Refers to inadequate and insufficient machine guards, unsafe workplace
conditions, unsafe work practices.
A . Biological

B. Chemical

C. Ergonomic

D. Safety

.
_____ 10. This is caused by organisms such as viruses, bacteria, fungi and parasites.
A . Biological

B. Chemical

C. Ergonomic

D. Safety

.

Check if your answers are correct by comparing them with those in
the Answer Key.
If you got 90-100% of the items correct, that means you
already familiar with the lesson covered by Learning Outcome No. 3.
However you may still study the lesson to refresh your memory and learn
new concepts.
If you missed a lot of items, do all the activities again to
gain knowledge and skills required for mastery.

MECHANICAL DRAFTING

135

Read the Information Sheet 1.1 very well then find out how much you can


OCCUPATIONAL SAFETY AND HEALTH
Occupational Safety and Health is a cross-disciplinary area concerned with
protecting the safety, health and welfare of people engaged in work or employment. As a
secondary effect, it may also protect co-workers, family members, employers, customers,
suppliers nearby communities, and other members of the public who are affected by the
workplace environment.

Occupational Health should aim to:
1. promote and maintain the highest degree of physical, mental and social well
being of workers in all occupations;
2. place and maintain the worker in an environment suitable to his physiological
and psychological capabilities;
3. protect workers from risk resulting from factors adverse to health; and
4. prevent workers from resignation due to health caused by poor working
conditions.
The reasons for establishing good occupational safety and health standards are
frequently identified as:





Moral – an employee should not have to risk injury at work, nor should others
associated with the work environment.
Economic – many governments realize that poor occupation and health per result
in cost to the State (e.g. through social security payments to the incapacitated,
costs for medical treatment, and the loss of the “employability” of the worker).
Economic studies human welfare in terms of the production, distribution, and
consumption of goods and services.
Legal – Occupational safety and health requirements may be reinforced in civil
law and/or criminal law.

Safety Standards are standards designed to ensure the safety of products, activities
or processes and others.
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OSHC Workplace Regulations
1. The place and all equipment and furnishings are maintained in thoroughly
safe, clean and hygienic condition and in good repair.
2. Keep the place free from rodents, cockroaches and other vermin.
3. Provide adequate facilities for hand washing, cleaning and disposing of
waste.
4. Establish proper procedures for infection control.
5. Keep the floor area and free from waste, water and grease.
6. Keep cabinets dry, clean and close tightly.

Self-Check 1.1

Directions: Identify the following terms below. Use a separate sheet of paper for
your answers.
__________ 1. The standards designed to ensure the safety of products, activities
or processes and others.
__________ 2. An employee should not have to risk injury at work, nor should
others associated with the work environment.
__________ 3. Occupational safety and health requirements may be reinforced in
civil law and/or criminal law.
__________ 4. A cross-disciplinary area concerned with protecting the safety,
and welfare of people engaged in work or employment.
__________ 5. It refers to human welfare in terms of the production, distribution, and
consumption of goods and services.


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137



One of the principal means of promoting efficiency in drafting is orderliness
and neatness. Efficiency in turn will produce accuracy in drawing. The drawing area should
be kept clear of equipment not in direct use.

Procedure in Setting up Drawing Tools, Materials and Equipment and
Standard Procedure
In preparation for a required task in Mechanical Drafting, student should plan,
prepare, and select tools and materials for a particular drawing activity. This is to ensure the
correct setting of standard procedure and accuracy of drawings.
The drawing tools, materials and equipment are very expensive items;
however these are important in all drafting tasks. Considering its cost and value in drafting
activity, it is also important to take care and maintain its usability.
With this, the following considerations are strictly emphasized as Standard Operating
Procedure during and after the utilization of the drafting tools, materials and equipment:
a. Before the start of drafting activity:
1. Select the tools, materials and equipment needed in the assigned task.
2. Properly set up the required tools and materials in a place convenient for you
to move and execute your work.
3. Clean the table and tools, see to it that these are free from dust and other
elements that would cause damage to your work.
4. Wash your hands with clean water.

TOOLS AND INSTRUMENTS ARE READY FOR THE ASSIGNED TASK
MECHANICAL DRAFTING

138

WORK PLACE AND DRAWING TABLES ARE READY FOR THE
ACTIVITY.
b. Activity proper:
1. Perform the activity by following the standard operating procedure per job
requirement.
2. Properly manipulate all the tools and equipment that are used in the activity.
3. In case errors or mistakes along the way (for instance misprinting of lines,
letters, and other forms of mistakes) use appropriate eraser.

STUDENTS DURING THE ACTUAL DRAFTING
ACTIVITY

MECHANICAL DRAFTING

139

c. After the activity:
1.
2.
3.
4.

Submit your output to your teacher for checking
Check all the tools and materials to ensure that nothing is lost.
Return the tools and materials to the tool keeper.
Withdraw your borrower’s card from the tool keeper and signed out that you
have returned the borrowed tools and materials.
5. Clean your work station before leaving.

CHECKING OF THE RETURNED TOOLS AND
INSTRUMENTS FOR PROPER SAFEKEEPING

CLEANING OF THE WORK STATION BEFORE LEAVING

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140

Other important Practices that must be observed in the work station or work place
There are important practices that must be observed in the work setting.
The following are:
1. Observe safety precautions:
a.
b.
c.
d.

Never smoke inside the work station.
Never use any tools and equipment without having it clean first.
Avoid talking with your co-students during working period.
Always turn off the lights, air condition, ceiling fan, computer units, and other
equipment before leaving the work station.
e. Maintain cleanliness in the work station.
f. Use tools and equipment properly.

2.
3.
4.
5.
6.

Observe punctuality of attendance.
Avoid quarreling with your co-students.
Observe and practice the value of respect.
Return the borrowed tools and equipment on time.
Observe and practice proper disposal of waste.

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141

Self-Check 1.2

Directions: List down some of the pointers and considerations done before, during and after
the activity in preparation for a required task in Mechanical Drafting. Use separate sheet of
paper.
A.

Before the start of drafting activity:

________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
B.

During the drafting activity:

________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
C.

After the activity proper:

________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________

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Keep Your Workplace Clean and Organized

It is important to consider safety measures whether in the industrial arts laboratory
shop, drafting room or in the home workshop. Good housekeeping is one of the sure ways to
keep a safe workplace. It is not the result of cleaning up once a week or even once a day. It
is the result of keeping the workplace cleaned-up all the time. It is an essential factor in a
good safety program, promoting safety, health, production, and morale.
Besides preventing accidents and injuries, good housekeeping saves space, time,
and materials. When a workplace is clean, orderly, and free of obstruction, work can get
done safely and properly. Workers feel better, think better, do better work, and increase the
quantity and quality of their work.
Japanese companies innovated a productivity philosophy called "5S," which stands
for five Japanese words that refer to a methodology not only for cleaning, but for business.
The 5S methodology is all about eliminating waste, speeding up daily tasks, and improving
the quality of the workplace. You can use the 5S methodology to help you organize your
tasks at the end of every working day.
Seiri (Sorting)
Take out unnecessary items and dispose. Keep only the items you need at work, and
discard or store everything else.

BIODEGRADABLE
MECHANICAL DRAFTING

DEGRADABLE
143

Seiton
"Set in order" means that there's a place for everything, and everything should be in
its place. Arrange necessary items in good order for use.

Seiso (Sweeping)
At the end of each working day, take time to clean up your office space. Clean up
any mess you make.

Seiketsu (Standardizing)
Maintain high standard of housekeeping

MECHANICAL DRAFTING

144

Shitsuke (Sustaining)
Do things spontaneously without being told or ordered.
A systematic and productive workplace is not a one-day-affair just because
somebody is observing
you.

The 5S system may sound simple, but it demands dedication and commitment. With
5S, you can be sure to complete your cleaning tasks in your workshop in no time.

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Self-Check 1.3
Direction: Match the different 5’s in Column A with illustrations or symbols in column
B. Write only the letter of the correct answer. Use a separate sheet of paper.
Column A

_______ 1. Shitsuke (Sustaining)

Column B

A

_______ 2. Seiso (Sweeping)

B
_______ 3.Seiketsu (Standardizing)

_______ 4.Seiton (Set in Order)

C

_______ 5. Seiri (Sorting)

D

E

F

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146


Since 1980’s, there were about 327,000 people employed in some type of drafting
job. Nine out of ten drafters work in industry. Many work in industries making machinery,
electrical equipment, and metal products. In the manufacturing sector most drafters work for
engineering or architectural consulting firms, construction companies, and public utilities.
Some work in local governmental agencies. In this case a student or an individual involved in
this kind of work should consider the following facts in the prevention of accidents and
hazards.
The Department of Labor and Employment ( DOLE) and the Occupational Health and
Safety Standards (OHSS) issued D.O. 13, ss 1998, known as the Guidelines Governing
Occupational Safety and Health in the Industry. It requires employers and establishments to
use a safety sign where there is a significant risk to health and safety that has not been
avoided or controlled by the methods required under other relevant law, provided the use of
a sign can help reduce the risk.

ACCIDENT PREVENTION SIGNS AND SYMBOLS
General
Signs and symbols required shall be visible at all times when work is being
performed, and shall be removed or covered promptly when the hazard no longer exists.
Danger Signs
Danger signs shall be used only where an immediate hazard exists. It should be read
as the predominating color for the upper panel; outline on the borders ; and a white lower
panel for additional sign wording.

BLACK

WHITE

BLACK

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147

Caution Signs
Caution signs shall be used only to warn against or caution against practices.
Caution sign shall have yellow as the predominating color; black upper panel and
borders; yellow lettering of “caution” on the black panel; and the lower yellow panel for the
additional sign wording.
Black lettering shall be used for additional wording.
Standard color of the background shall be yellow ; and the panel, black with yellow
letters. Any letter used against the yellow background shall be black. The colors shall be
those of opaque glossy samples.

YELLOW

BLACK

Exit Signs
Exit signs, when required, shall be lettered in legible red letters, not less than 6
inches high, on a white field and the principal stroke of the letters shall be at least threefourths in width.

RED
WHITE

Safety Instructions Signs
Safety instruction signs, when used, shall be with green upper panel with while letters
to convey the principal message. Any additional wording on the sign shall be black letters on
the white background.

WHITE
GREEN
BLACK

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148

Directional Signs
Directional signs, other than automotive traffic signs specified shall be white with a
black panel and white directional symbol. Any wording on the sign shall be black letters on
the white background.

WHITE
BLACK

Traffic Signs

Construction areas shall be posted with legible traffic signs at point hazard.
All traffic control signs or devices used for protection of construction workers shall
conform to Occupational Safety and Health Administration (OSHA) standards.

MECHANICAL DRAFTING

149

Table shows other signs and symbols you have to follow at all times while doing your
works inside and outside the shop.

Example

Classification

Meaning/ Usage

Prohibition

Do not use in any specified places. It may
interfere in the operations of other electronic
gadgets in the vicinity

Hazard alerting

BE CAREFUL Warning. It warns everybody
of potential dangers around the workplace.

Prohibition

NOT ALLOWED Danger, alarm. This
prohibition reduces risks of fire and prevents
personal injury.

Prohibition

When you see this symbol, picking, smoking,
or touching is prohibited

Hazard alerting

Do not perform any activity when your eyes
are unprotected.

Hazard alerting

Danger of electrocution. Do not ignore this
sign in the workplace.

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150

Hazard

Avoid getting into contact to places,
equipment or tools with this sign.
alerting

High voltage is dangerous and fatal.
Keep out of areas where you see signs like
alerting this.
Hazard

Safety

In all offices, workplaces, and
establishments, it is mandatory to have this
sign for first aid displayed on conspicuous
places. This is where you should run to if
accidents happen.

For good housekeeping, these
Hazard symbols indicate “recycling” materials. This
avoidance/
means that the material is recyclable or
safety
where you should place recyclable
objects/wastes in the work area.

Hazard
Avoidance

MECHANICAL DRAFTING

Be careful with falling objects and
from being pressed from lathe and other
moving machines

151

Self-Check 1.4

Directions: Match Column A with Column B. Write only the letter of the correct
answer on a separate sheet of paper.
Column A

1.

DIRECTIONAL SIGN
__________

2.

C

SAFETY SIGN

__________

5.

B

EXIT SIGN

__________

4.

A

CAUTION SIGN

__________

3.

Column B

D

DANGER SIGN

E
__________


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152



Hazards in the Workplace
There are many things that affect the health of a person, such as his environment,
his lifestyle, etc. Work is an important determinant of health. It can influence health in a
positive or in a negative way.
A place that is safe, healthy and work-conducive entails more productivity. In fact,
with a healthy workplace you will be doing more work with less effort.
Hazard is a term used to describe something that has the potential to cause harm.
Risk on the other hand, is a measure of the possibility of a specific harmful effect in
given circumstances. It is very important to know the difference between a hazard and a risk.

Types of workplace hazards include:
 Safety hazards - Inadequate and insufficient machine guards, unsafe workplace

conditions, unsafe work practices.
 Biological hazards - Caused by organisms such as viruses, bacteria, fungi and

parasites.
 Chemical hazards - Solid, liquid, vapor or gaseous chemicals, dust, fume or mist.
 Ergonomic hazards - Anatomical, physiological, and psychological demands on the
worker, such as repetitive and forceful movements, vibration, extreme temperatures,
and awkward postures arising from improper work methods and improperly designed
workstations, tools, and equipment.
 Physical hazards - Noise, vibration, energy, weather, electricity, radiation and
pressure.
 Psychological hazards - Those that are basically causing stress to a worker. This kind
of hazard troubles an individual very much to an extent that his general well-being is
affected.
What are examples of a hazard?
Workplace hazards can come from a wide range of sources. General examples
include any substance, material, process, practice, etc that has the ability to cause harm or
adverse health effect to a person under certain conditions. See Table 1.

MECHANICAL DRAFTING

153

Table 1
Examples of Hazards and Their Effects
Workplace Hazard

Example of Hazard

Example of Harm Caused

Thing

Knife

Cut

Substance

Benzene

Leukemia

Material

Asbestos

Mesothelioma

Source of Energy

Electricity

Condition

Wet floor

Slips, falls

Process

Welding

Metal fume fever

Practice

Hard rock mining

Silicosis

Shock,
electrocution

As shown in Table 1, workplace hazards also include practices or conditions that
release uncontrolled energy like:






an object that could fall from a height (potential or gravitational energy),
a run-away chemical reaction (chemical energy),
the release of compressed gas or steam (pressure; high temperature),
entanglement of hair or clothing in rotating equipment (kinetic energy), or
contact with electrodes of a battery or capacitor (electrical energy).

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154

SAFETY HAZARDS

CHEMICAL HAZARDS

PHYSICAL HAZARDS

MECHANICAL DRAFTING

BIOLOGICAL HAZARDS

ERGONOMIC HAZARDS

PSYCHOLOGICAL HAZARDS

155

Self-Check 1.5

Direction. Select from the list below the type of workplace hazard that matches the given
definition or description. Use separate sheet of paper.

BIOLOGICAL
PHYSICAL

CHEMICAL
PSYCHOLOGICAL

ERGONOMIC
SAFETY

______________________ 1. Refers to Inadequate and insufficient machine guards,
unsafe workplace conditions, unsafe work practices.
______________________ 2. This is caused by organisms such as viruses,
bacteria, fungi and parasites.
______________________ 3. Some examples of this type of hazard are solid, liquid,
vapor or gaseous substances, dust, fume or mist.
______________________ 4. Anatomical, physiological, and psychological demands
on the worker, such as repetitive and forceful
movements, vibration, extreme temperatures, and
awkward postures arising from improper work
methods and improperly designed workstations, tools,
and equipment.
______________________ 5. Noise, vibration, energy, weather, electricity, radiation
and pressure.


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156

LEARNING OUTCOME 2
Select and Use personal protective clothing and devices

PERFORMANCE
STANDARDS
1. Personal protective clothing/equipment (PPE) identified as per job
requirements
2. Proper wearing of PPE are properly observed in accordance with workplace
safety policies.

Materials
a.
b.
c.
d.

Drawing paper
Pencil
Any coloring medium
PPE’s

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157

Let us determine how much you already know about personal protective clothing
and devices. Take this test.

Pretest LO 2
A. Multiple Choice. Write the letter of the correct answer.
_____ 1. The main purpose of wearing this kind of PPE is to protect our limbs and body from
metal dusts, flaming combustion, flying chips, minute particles and stray metallic
objects from abrasive wheels, drills and cutting tools
A. Cover all B. Protective Headgear
C. Safety goggles
D. Safety
shoes
_____2. A safety helmet or wide-brimmed hat for head protection..
C. Safety goggles
shoes

D. Safety

_____3. A pair of protective coverings for the hands, usually with separate divisions for the
fingers and for the thumb.
A. Apron
B. Gloves
C. Goggles
D. Pot holder
.
_____ 4. Safety shoes in the shop designed specifically with hard or metallic materials in the
toe areas.
C. Safety goggles
D. Safety shoes
_____5. This is a protective instrument for the eyes with transparent eye-pieces.
C. Safety goggles
D. Safety shoes
B.

Directions: Write T if the statement is True and F if the statement is False. Use
_____ 1. Protective helmets must be worn only where there is a risk of falling debris.
_____ 2. The equipment should be well maintained and stored correctly.
_____ 3. A respirator may be required in all workplaces.
_____ 4. Aprons, gloves and shields are necessary where there is possible spillage or
splashes of chemical, blood or other hazardous material.
_____ 5. Mechanical Drafting requires headwork and must be done in quiet
surroundings.
Check if your answers are correct by comparing them with those in the
Answer Key.
If you got 90-100% of the items correct, that means you already familiar
with the lesson covered by Learning Outcome No.2. However you may still
study the lesson to refresh your memory and learn new concepts.
If you missed a lot of items, do all the activities to gain knowledge and
skills required for mastery.

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158


Mechanical Drafting requires headwork and must be done in quiet surroundings. But
sometimes they are also going outside to see the actual project site they are developing and
planning for. They have to think and explore other design that will fit the needs of present
technology. In this case they must be aware of using the PPE.
Personal Protective Equipment (PPE)
Using personal protective equipment (PPE) helps to prevent the transmission of
communicable diseases between patients and health care providers. It can also help to
prevent the contamination of exposed wounds or sores from germs or bacteria that can
travel from a health care provider to the patient. Knowing how to properly use PPE can help
to insure the safety and well-being of health care providers and emergency responders.

Engineering and administrative controls are not exempted in the different hazardous
things normally happened in the workplace, the use of Personal Protective Equipment (PPE)
protects workers from injury. Personal Protective Equipment must be used and worn in many
work situations in order to protect employees from harm.
Types and Uses

Symbol

Name of Personal
Protective Equipment

Uses and Functions

Protective Headgear

A safety helmet or widebrimmed hat for head protection.
This can be used by a draftsman
during the actual visitation of the
project site.

Over-all or Cover-all

The main purpose of
wearing this kind of clothing is to
protect our limbs and body from
metal dusts, flaming combustion,
flying chips, minute particles and
stray metallic objects from
abrasive wheels, drills and
cutting tools.

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159

Safety Boots or

In most cases, safety
shoes in the shop are designed
specifically with hard or metallic
materials in the toe areas.

Gloves

A pair of protective
coverings for the hands, usually
with separate divisions for the
fingers and for the thumb.

Shoes

Safety Glasses or
Goggles

Fire extinguisher

This is a protective
instrument for the eyes with
transparent eye-pieces. It also
protect the eyes from absorbing
so much light

A portable device
containing chemicals that can be
sprayed on a fire to put it out.

Personal Protective Equipment Inspection Checklist
Here are some requirements with which workplaces must abide
Assessments
 A hazard assessment will identify when PPE needs to be used, in what
circumstances, and who must wear it.
Maintenance




The equipment should be well maintained and stored correctly. It must be
repaired or replaced when necessary.
Protective helmets must be worn where there is a risk of falling debris.
Aprons, gloves and shields are necessary where there is possible spillage or
splashes of chemical, blood or other hazardous material.

MECHANICAL DRAFTING

160








Protective, steel-toe boots should be worn where there is a risk of damage to
a worker's feet.
Goggles or other eye-protection devices should be worn whenever there is a
danger of the eyes being splashed or damaged in the course of work.
Compliance
Safety boots or head-protection equipment is worn, it must comply with the
Standards Safety Requirements.
A respirator may be required in some workplaces.
Eye wash material will need to be kept on the site where there is a danger of
splashes in the eyes. Where PPE such as goggles or safety helmets are
required, a notice to this effect should be posted at the entrance to the
workplace.

MECHANICAL DRAFTING

161

Self-Check 2.1

Direction:

Identify the following Personal Protective Equipment PPE as show

below:

2

3
1

4

5


MECHANICAL DRAFTING

162


Operation Sheet 1.1
Tools and Materials
 Drawing paper
 Pencil
 Any coloring medium
Direction:
Design a poster showing the proper use of PPE including the drawing tools and
instruments used in the shop. You are free to choose any available colouring medium.
The poster should be informative and should clearly show the main message. You will
need to undertake some research to complete this activity.
Your poster/ could focus on:
 Hazard identification and risk assessment in general;
 The responsibility of your teacher and you as a student.
2. Your work will be graded based on the Evaluation Sheet given.
1.

MECHANICAL DRAFTING

163


HOW WELL DID YOU PERFORM?
Criteria for Assessment: Analytic Rubrics Scoring

CRITERIA

5 points

3 points

1 point

Theme

The output
is very relevant to
the theme

The output is
moderately relevant
to the theme

The output is
quite relevant to the
theme

Originality

The idea or
concept is very
original

The idea or
concept is
moderately original

The idea or
concept is quite
original

Visual Impact

The output
is very attractive

The output is
moderately attractive

The output is
quite attractive

Neatness

The output
is free from any
erasures

The output
has one to three
erasures

The output
has four or more
erasures

Rating Scales
POINTS EARNED

NUMERICAL

DESCRIPTIVE

15 – 20

90 – 100

Very Good

10 - 14

86 – 90

Good

5-9

81 - 85

Fair

1-4

75 - 80

MECHANICAL DRAFTING

Needs
Improvement

164

Congratulations! You did a great job!

REFERENCES
LO1
Giesecke, Mitchell, Spencer. Hill and Dygdon, Technical Drawing Eight
Edition; The Macmillan Company: 1999
 Competency Based Learning Material, Civil Technology
 Competency Based Learning Material, Drafting Technology
 Competency Based Learning Material, Machine Shop
 Industry, Department of Labor and Employment – Bureau of Working
Conditions, D.O. 13, s. 1998.
 Procedural Guidelines Governing Occupational Safety and Health in the
Construction
 http://en.wikipedia.org/wiki/Occupational_safety_and_health
 http://www.aabr.org.au/vcn/12 2risks.htm
 http://www.cchs.oshanswers/hsprograms/hazardrisk.html
 http://www.ehow.com/list_6926722_personal-protective-equipmentchecklist.html
 http://www.sofweb.vic.edu.au/safe@work
 www.workcover.nsw.gov.au.
Lo 2
Giesecke, Mitchell, Spencer. Hill and Dygdon, Technical Drawing Eight
Edition; The Macmillan Company: 1999
Competency Based Learning Material, Civil Technology
Industry, Department of Labor and Employment – Bureau of Working
Conditions, D.O. 13, s. 1998.
Procedural Guidelines Governing Occupational Safety and Health in the
Construction
http://en.wikipedia.org/wiki/Occupational_safety_and_health
http://www.ehow.com/list_6926722_personal-protective-equipmentchecklist.html
http://www.sofweb.vic.edu.au/safe@work
www.workcover.nsw.gov.au.


MECHANICAL DRAFTING

165

ANSWER KEY LESSON 1
LO1. Identify drafting materials and tools/drawing instruments applicable to a
specific job.
PRE-TEST
A.
1.
2.
3.
4.
5.

C
C
D
A
B

1.
2.
3.
4.
5.

E
A
D
B
C

B.

SELF CHECK 1.1

M
A
S
K
I

R
O
T
C
A
R
T
O
R
P

S
L
I
C
N
E
P
G
N
I
W
A
R
D

R E
D
R
A
W
A
N
G G S E
P
T
A
A
P
E
R

N E

P

R A

H S

L

I

C
C

N E P

O
M
E

P
R

L

A

A
A C

S

S
C
E

I

R T

E

M

R
P

D
E

L
E
I
H

T

R I

A

T

S
N G L
N

E

I
S

A
R
E

Q
U
A

S

R
E
D
I
V
I
D

R
E

MECHANICAL DRAFTING

166

ANSWERS:
1. COMPASS
2. DIVIDER
3. DRAWING PAPER
4. DRAWING PENCILS
5. ERASER
6. ERASING SHIELD
7. MASKING TAPE
8. METRIC SCALES
9. PENCIL SHARPENER
10. PROTRACTOR
11. TRIANGLES
12. T SQUARE
LO2. Request, receive and inspect drafting materials and tools/drawing instruments.
PRE-TEST
1.
2.
3.
4.
5.

A
C
D
B
C

SELF CHECK 2.1
A.
Column A

1.

ROIFYVT MNOENF

Column B

1. INVENTORY FORM

2. RLVCDPYT EEEEIIR

2. DELIVERY RECEIPT

3. PRESO ROBRWIL

3. BORROWER SLIP

4. SODEAR CUPREAH

4. PURCHASE ORDER

5. FITIMEON SIRUROQ

5. REQUISITION FORM

B. Teachers Check

MECHANICAL DRAFTING

167

ANSWER KEY Lesson 2
LO1. Select and use measuring instruments
PRE-TEST
1. C
2. C
3. D
4. C
5. D
6. B
7. D
8. A
9. B
10. B
SELF CHECK # 1.1
A.
1.
2.
3.
4.
5.

C
E
D
A
B
B.

1.
2.
3.
4.
5.

Triangle
Tape ruler
Protractor
T-Square
Divider

LO2. Clean and store measuring instruments
PRE-TEST
A. Multiple Choice

1.
2.
3.
4.
5.

F
E
D
A
B

MECHANICAL DRAFTING

168

B. Uses and Care of Drafting measuring tools











Be sure to inspect tools before using them. This is to check if they are in working
After using a tool, clean it thoroughly with a damp cloth. Wipe it dry with another
When not in use, the T-square is preferably hung by inserting the hole to a nail
Do not abuse or misuse any piece of drawing instruments.
Avoid throwing a tool to anybody; instead, hand it overto him carefully.
Avoid setting off the distances individually by moving the scale to a new position from
Avoid unnecessary sliding of T-square or triangles protect the drawing. Pick up the
Do not pull too much the steel tape of pull-push rule to the coil spring from damage.
Oil the movable parts of the measuring tools such as zigzag rules, calipers, dividers,
Report defective measuring tools and any hazard to instructor immediately.
SELF -CHECK # 2.1
A.
1.
2.
3.
4.
5.

T
T
T
T
T
B. Uses and Care of Drafting or measuring tools












Be sure to inspect tools before using them. This is to check if they are in working
After using a tool, clean it thoroughly with a damp cloth. Wipe it dry with another
When not in use, the T-square is preferably hung by inserting the hole to a nail
Do not abuse or misuse any piece of drawing instruments.

Avoid throwing a tool to anybody; instead, hand it overto him carefully.
Avoid setting off the distances individually by moving the scale to a new position from
Avoid unnecessary sliding of T-square or triangles protect the drawing. Pick up the
Do not pull too much the steel tape of pull-push rule to the coil spring from damage.
Oil the movable parts of the measuring tools such as zigzag rules, calipers, dividers,
Report defective measuring tools and any hazard to instructor immediately.

MECHANICAL DRAFTING

169

LO3. Convert fraction to decimal and vice versa
PRE-TEST
TEST I. A. Convert fractions into decimals
1.
. 25
2.
.75
3.
.0.4375
4.
.375
5.
.125
B. Convert decimals into fractions .
6.
7/50
7.
6/25
8.
¾
9.
1/8
10.
3/20
C. Round off the following numbers to their nearest hundredths.
11.
76.35
12.
93.67
13.
27.01
14.
4.62
15.
5.25
SELF -CHECK # 3.1
A.
1.
2.
3.
4.
5.

. 25
.75
.0.4375
.375
.125

B.
1.
2.
3.
4.
5.

13.76
38.61
41.01
8.62
7.25

C.
1. 1/5
2. 4/5
3. 21/25
4. 7/50
5. 6/25
6. ¾
7. 1/8
8. 3/20
9. 13/20
10. 3/8

MECHANICAL DRAFTING

170

LO4. Convert English to Metric measurement and vice versa
PRE-TEST
A.
1.
2.
3.
4.
5.

9.84 inches
206.69 or 206.70 feet
15.24 meters
4. 0.33 meters
5. 0.39 inch

B.
6. 1” 1/16
7. 3/8
8. 13/16”
9. 2.1 cm
10. .75 cm

SELF -CHECK # 4.1
A.
1.
2.
3.
4.
5.
6.

13/16
5/8
5/16
¾
1-7/8
2-1/2

7.
8.
9.
10.

13 mm or 1.3 cm
37 mm or 3.7 cm
4 mm or .4 cm
75 mm or .75 cm

B.

II.
1.
2.
3.
4.
5.

23.52 or 24 inches
8.89 cm
.75 cm.
25.4 cm.
0.98 or 1 ft

MECHANICAL DRAFTING

171

ANSWER KEY – LESSON 3

LO1. Identify Detailed and Assembly Drawing.

PRE-TEST
A. 1. A
2. B
3. D
4. A
5. D
6. B
7. D
8. A
9. B
10. C
11. A
12. B
13. A
14. A
15. D

SELF-CHECK 1.1

A.
B.
C.
D.
E.
F.
G.

Leader line
Dimension line
Extension line
Hidden line
Dimension line
Hidden line
Object line

H. Hidden line
I. Object line
J. Leader line
K. Cutting-plane line
L. Object line
M. Extension line
N. Object line

SELF-CHECK 1.2
Teacher check

MECHANICAL DRAFTING

172

SELF-CHECK 1.3
1.
2.
3.
4.
5.
6.
7.

First-Angle Projection
Front View
Third-Angle Projection
Top View
Height
Width
Depth

SELF-CHECK 1.4
1. Orthographic projection
2. First quadrants
3. Second quadrant
4. Third quadrant
5. Fourth quadrant
6. First quadrant
7. Third quadrant
8. Horizontal plane
9. Frontal plane
10. Profile plane
SELF-CHECK 1.5
1.
2.
3.
4.
5.
6.
7.
8.

A - Pictorial drawing
D - Station point
B – Vanishing point
C – Man’s-eye view
B – Cavalier oblique
Measure
Isometric
Non-Isometric lines

SELF-CHECK 1.6
1.
2.
3.
4.
5.

B – Oblique drawing
B – Cavalier projection
B – 45 degrees
A – Cabinet projection
(At least three of the four given rules are the answers in any order. )
5.1 Avoid positioning the longest side of the object to the picture plane.
5.2 Place the circular and irregular surfaces of the object parallel to the picture
plane.
5.3 Dimensions on the receding axis of the cabinet drawings should be reduced to ½
or 2/3.
5.4 If there is no given orthographic views, always proportion the details of the
drawing to those of the actual object.

MECHANICAL DRAFTING

173

SELF-CHECK 1.8
1. Enlarge scale
2. Enlarge scale
3. Reduce scale
4. Full scale
5. Reduce scale
6. Enlarge scale
7. Reduce scale
8. Enlarge scale
9. Reduce scale
10. Enlarge scale

SELF-CHECK 1.9
1.
2.
3.
4.
5.
6.
7.

D – Size dimension
A – Location dimension
C – Over-all dimension
A – Dimensioning
A – Aligned method
A – Detail dimension
D – Uni-directional method
SELF-CHECK 3.10
( Figure 3 ) Vee Block

Vee Block

Part

Name

1

Body

1

TWS – 8 Gray Cast Iron

2

Yoke

1

ASTM 603 Forging Steel

3

Thumb screw

1

S.A.E. 1060 H.R.S.

MECHANICAL DRAFTING

Quantity

Material

174

ANSWER KEY – LESSON 4
LO1. Identify hazardous area
PRE-TEST
1. A
2. B
3. A
4. C
5. A
6. D
7. D
8. B
9. B
10. A

SELF CHECK # 1.1
1.
2.
3.
4.
5.

Safety Standards
Moral
Legal
Occupational Safety and Health
Economic

SELF CHECK # 1.2
A. Before the start of drafting activity:





Select the tools, materials and equipment which are needed in the assigned
task.
Properly set up the required tools and materials in a place which is
convenient for you to move and execute your work.
Clean the table and tools, see to it that these are free from the dust and other
elements that would cause damage to your work.
Wash your hand with clean water.

B. Activity proper:
 Perform the activity by following the standard operating procedure per job
requirement.
 Properly manipulate all the tools and equipment that are used in the activity.
 In case of errors or mistakes along the way ( for instance misprinting of lines,
letters, and other forms of mistakes) use appropriate eraser.
C. After the activity:
 Submit your output to your teacher for checking
 Check all the tools and materials to ensure that nothing has lost.
 Return the tools and materials to the assigned tool keeper for safekeeping.
 Withdraw your borrower’s card from the tool keeper and signed out that you
have returned the borrowed tools and materials.
MECHANICAL DRAFTING

175

 Clean your work station before leaving.
SELF CHECK # 1.3
1. B
2. C
3. A
4. D
5. E

1.
2.
3.
4.
5.

SELF CHECK # 1.4
C
A, B or D
E
A, B or D
A or D
SELF CHECK #1.5

1.
2.
3.
4.
5.

SAFETY HAZARDS
BIOLOGICAL HAZARDS
CHEMICAL HAZARDS
ERGONOMIC HAZARDS
PHYSICAL HAZARDS
LO2. Use personal protective clothing
PRE-TEST

A. 1. A
2.
3.
4.
5.

B
B
D
C

B. 1. F
2.
3.
4.
5.

T
F
T
T

SELF CHECK # 2.1
1.
2.
3.
4.
5.

Appropriate clothing such as over-all / cover-all
Protective Headgear
Safety Glasses or Goggles
Gloves
Safety Boots or Shoes

MECHANICAL DRAFTING

176

LIST OF MATERIALS / TOOLS/ EQUIPMENT/ CONSUMABLES
FOR THIS MODULE
Drafting Materials










Drawing Paper
Drawing or Pen Ink
Masking Tape
Pencil-Ink Eraser
Pencil Sharpener
Pentel Pen
Poster Color / Water Color / Coloring Pen or Pencils
Tracing Paper
CD/ DVD Tapes
Drafting Tools and Instruments
















Drawing Pencil ( Hard, Medium, Soft )
Erasing Shield
Triangular Scales
Compass
Divider
Drawing Templates
French Curve
Protractor
Ruler
Scales
Tape or Tape Ruler
Technical pens / Drawing Pen /Sign Pen
T- Square
Triangles
Equipment







Computer Hardware
Drawing Table /Drawing Board
White Board
Printer
LCD Projector
Learning Materials

 Multimedia Materials (print, video, audio )
 Bibliography

MECHANICAL DRAFTING

177

Acknowledgement
This Learning Module was developed for the Exploratory Courses in Technology and
Livelihood Education, Grades 7 and 8 of the K to 12 Curriculum with the assistance of the
following persons:
This Learning Module on MECHANICAL DRAWING NC I was developed by the
following personnel:
MODULE WRITERS
DANTE B. BERMAS
Pres. Sergio Osmena High School
Division of City Schools - Manila
National Capital Region (NCR)

MIRASOL F. DASIG
San Pedro Relocation Center N H.S.
San Pedro, Laguna
Region IV-A, Calabarzon
REVIEWERS

GIL P. CASUGA
Chief TESD Specialist

REYNALDO S. DANTES
Senior TESD Specialist

BERNADETTE S. AUDIJE

MARIA A. ROQUE

AIDA T. GALURA
VSA II, ACNTS

VICTORIO N. MEDRANO
Principal IV, SPRCNHS

PARALUMAN R. GIRON, Ed.D.
Chair, Sub-TWG on K to 10

BRENDA B. CORPUZ, Ph.D.
TA for K to 12 Curriculum

OFELIA O. FLOJO
Retired Assistant Chief, EED, RO IV-A

RODERICK AGUIRRE, Ph.D.

BEATRIZ A. ADRIANO
Principal IV, ERVHS

DOMINGA CAROLINA F. CHAVEZ
Principal II, MBHS
DOCUMENTORS / SECRETARIAT

PRISCILLA E. ONG
K to 12 Secretariat

FREDERICK G. DEL ROSARIO
Head Teacher III, BNAHS

EMMANUEL V. DIONISIO
Head Teacher III, AFGBMTS

LYMWEL P. LOPEZ
Teacher I, AFGBMTS

DANTE D. VERMON JR.
Teacher I, AFGBMTS

CHERLYN F. DE LUNA
Teacher I, AFGBMTS

LOUIE B. ANGELES
Teacher I, BNAHS

JOANNA LISA C. CARPIO
Teacher I, , BNAHS

Dir. IMELDA B. TAGANAS
Executive Director, Qualifications Standards Office
K to 12 Learning Area Team Convenor, TLE/TVE
MECHANICAL DRAFTING

178

K to 12 mechanical drafting learning module

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