N.I.S.T is another big one

the "Federal Specification" as opposed to Federal Standard, or anything else
for granite surface plates is GGG-P-463c. Federal Specification coverage for
master, calibration, inspection, and workshop gage block tolerance grades
are under GGG-G-15C, March 20, 1975, which supercedes GGG-G-15B, Nvember 6,
1970.. Can't find or can't get in the www