Adjustable snap gauges are used for checking large size shafts made with horseshoe shaped frame of I section. In an adjustable snap gauge, two adjustable jaws are provided on one side and one fixed anvil on the other side. The distance between the two anvils is adjusted by adjusting the adjustable anvils by means of setscrews. This adjustment can be made with the help of slip gauges for specified limits of size.

Feeler gauges are used:
– To check the gap between the mating parts
– To check and set the spark plug gaps
– To set the clearance between the fixture (setting block) and the cutter/tool for machining the jobs
– To check and measure the bearing clearance, and for many other purposes where a specified clearance must be maintained.