PRECISION MEASURING AND GAGING - OD1642 - LESSON 1/TASK 2
instruments and indicating gages and verifying inspection gages.
blocks are used to verify the accuracy of ring and snap gages and many other
special-purpose gages. The classification of blocks depends largely on the
accuracy required. Typical classification is as follows:
The following steps should be followed when caring for
precision gage blocks:
Step 1. Observe particular care when using gage blocks to measure hardened
work. The danger of scratching is increased when the work is as hard as the
block, or harder.
Never touch the measuring surfaces of the blocks any more than
The moisture from one's hands contains acid which, if not
removed, will eventually stain the blocks.
Step 3. Before using the gage blocks, ensure that there is no grease, oil,
dirt, or other foreign substances on the block.
Step 4. Every time a set of blocks is used, all of the blocks which have
been cleaned for use must be covered with a light film of acid-free oil,
such as boiled petroleum, before they are put away. Wipe them with an oiled
chamois as the blocks are returned back to their places in the case.