MS21132A, MILITARY STANDARD: WRENCHING ELEMENT, EXTERNAL HEXAGON, FOR THREAD FASTENERS (25 MAR 1987) [SUPERSEDED BY NASM21132]
MS21132A, MILITARY STANDARD: WRENCHING ELEMENT, EXTERNAL HEXAGON, FOR THREAD FASTENERS (25 MAR 1987) [SUPERSEDED BY NASM21132].