MS9557D, MILITARY STANDARD: BOLT, MACHINE-DOUBLE HEXAGON EXTENDED WASHER HEAD, CORROSION AND HEAT RESISTANT STEEL, .250-28 UNJF-3A (20 NOV 1993) [SUPERSEDED BY SAE-AS9557}.
MS9557D, MILITARY STANDARD: BOLT, MACHINE-DOUBLE HEXAGON EXTENDED WASHER HEAD, CORROSION AND HEAT RESISTANT STEEL, .250-28 UNJF-3A (20 NOV 1993) [SUPERSEDED BY SAE-AS9557}.