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″.

Dynabrade 78424 4-1/2" Dia. x 3/8" Medium DynaBrite Surface Conditioning Disc, 25/pack
3M 26120, PPS Series 2.0 Adapter, Type S28, 17.5 mm Female, 19 TPI
Thread, 7100135956
Dynabrade 53270 7" (180 mm) Dia. Right-Angle Disc Sander
3M 26119, PPS Series 2.0 Adapter, Type S27, 16 mm Male, 1.5 mm Thread, 7100135925
Insize HDT-PB350, HAMMER IMPACT BRINELL HARDNESS TESTER, 6940561966657
3M 26140, PPS Series 2.0 Adapter, Type S45, 1/4 Female, 19 Thread BSP, 7100135336 