This document discusses different methods of indexing used in milling operations. It describes simple indexing which divides the workpiece into more divisions and rotates it in smaller increments with each turn of the crank. It provides examples of indexing plates used by Brown and Sharpe and Cincinnati and Parkinson heads that have different hole patterns for indexing divisions. It also discusses calculating indexing divisions and provides an example of calculating indexing for 35 divisions. Finally, it briefly explains compound indexing which uses two circles on the indexing plate to calculate the indexing fractions.