AN531 (REV. 5), AIR FORCE-NAVY AERONAUTICAL STANDARD: SCREW, TAPPING, THREAD FORMING OR THREAD CUTTING, 82 DEG., FLAT HEAD, SPACED THREAD (17 FEB 1959)
AN531 (REV. 5), AIR FORCE-NAVY AERONAUTICAL STANDARD: SCREW, TAPPING, THREAD FORMING OR THREAD CUTTING, 82 DEG., FLAT HEAD, SPACED THREAD (17 FEB 1959).