For zero setting of inside micrometers, three points internal micrometers and bore gages.
Deviation is the difference between the ordered size and the size marked on the setting ring when supplied.
For example, the ordered size is .2”, the size marked on the setting ring when supplied may be .20008″.
setting ring when supplied may be .20008″.

Insize 6318, CALIPER/MICROMETER GRINDING MACHINE (caliper grinding blocks are included), 6940561953862
3M 26120, PPS Series 2.0 Adapter, Type S28, 17.5 mm Female, 19 TPI
Thread, 7100135956
Air Turbine Tools 200SV - 3mm Straight Hand Tool Series with Brake, 50,000 RPM, 32063
Dynabrade 97570 1/2" NPT Female Safety Coupler 