multi-hole reference standard 29 holes 1/8, 5/32, 3/16, 7/32, 1/4, 9/32, 5/16, 11/32, 3/8, 13/32, 7/16, 15/32, 1/2, 17/32, 9/16, 19/32, 5/8, 31/32, 11/16, 23/32, 3/4, 25/32, 13/16, 27/32, 7/8, 29/32 15/16, 31/32 0.020 deep through notch 3 surface flaws...
