The average life expectancy of a gage block is about 3 years. The primary causes for
scrapping gage blocks are corrosion and mishandling.
There is no magic in preserving your gage blocks. Here are a few commonsense suggestions
you can use.
1) Keep the blocks clean. After using the gages, wipe them all over with a chamois or soft
cloth, holding the gages in such a manner that the hands and fingers never come in contact
with the blocks. When placing the gages back in their case, do not touch the gages with
2) Keep steel blocks coated with a rust preventative oil such as Starrett M-1 when not in use.
It is recommended that if the gages are going to be stored overnight or be taken out of use,
that they be wiped all over with a chamois dampened with a rust preventative oil such as
Starrett M-1. Use the handling procedure as above, and do not touch the blocks during
handling or placing them in their case.
3) Before use, we recommend cleaning the gages with mineral spirits. Mineral spirits leaves a
slight oily film which can offer short term corrosion protection while the blocks are in use.
(The slight oily film left by the mineral spirits will not affect the use of the block.)
Cleaning blocks with alcohol is acceptable, but may leave the blocks so clean they may be
susceptible to corrosion. Also alcohol is a greater fire hazard than mineral spirits.
4) Before wringing gage blocks together, check the blocks for nicks and burrs.
Click here to go to recommended procedure on stoning gage blocks.
Note: Do no leave blocks wrung together overnight.
5) Keep blocks away from an open case during use. Do not handle, clean, use, or wring
blocks above an open case. Blocks falling onto other blocks will not only damage the
dropped block, but will likely damage other blocks in the case.
6) Examine the instrument or equipment that you are going to check with the gage blocks for
nicks and burrs. Any nicks and burrs may not only damage the gage blocks, they can also
give erroneous readings during the check.
7) Handle gage blocks as the precision instruments that they are. Their accuracies range
down to a few microinches which is about 1/1000 the thickness of a human hair. Blocks
cannot be tossed around, used as wedges, hammered, and be expected to retain their
8) Consider the use of "wear" blocks if blocks are going to be placed into situations where
they might become scratched or nicked. Click here to go to section on wear blocks.