5306-00-281-9972 (B6812)
NSN 5306-00-281-9972 (NIIN 00-281-9972) is a machine bolt in Federal Supply Class 5306, Bolts — an externally threaded fastener designed for insertion through holes in assembled parts and normally intended to be tightened or released by torquing a nut. Manufacturer part number B6812 (Military Specifications, CAGE 81349); also referenced as NAS428K5-12, NAS438K5-12 (National Aerospace Standards).
Key specs: finished head; 26 rockwell c minimum and 32 rockwell c maximum overall hardness; full characteristics table below. NIIN assigned January 1963; DEMIL A (none required). Supersedes 5306-00-637-8540 (1969).