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″. 
Related products
Measuring/ Inspection Instruments
Insize 4120-2, METRIC THREAD RING GAGE, GO, M2x0.4, 6928640341342
	$72.96
	
			
		Measuring/ Inspection Instruments
Insize 4120-20N, METRIC THREAD RING GAGE, NO GO, M20x2.5, 6928640341823
	$59.18
	
			
		Measuring/ Inspection Instruments
Insize 4120-18, METRIC THREAD RING GAGE, GO, M18x2.5, 6928640341502
	$70.70
	
			
		
Dynabrade 78198 3" Dia. x 80 Grit A/O DynaCut Locking-Type Disc, 2 Ply Cloth, 25/pack						
Dynabrade 61420 Raptor Vac Electric Portable Vacuum System						
Dynabrade 95821 Dynabrade Air Lube 10W/NR, 4oz Bottle						
Dynabrade 95843 Dynabrade Air Lube 10W/NR, 1 Gallon						
3M 01328, PSA Cloth Disc 348D, P180 X-weight, 3 in x NH, Die 300V, 7000045068						
Dynabrade 13509 Dynastraight Finishing Tool, Rear Exhaust, 6,000 RPM, 5/8" (16 mm) or 1" (25 mm) Dia. Arbor						
Insize 4120-20N, METRIC THREAD RING GAGE, NO GO, M20x2.5, 6928640341823						