Used on 60mm m2 and m5 mortar mount. right-hand 24 thread quantity per inch diamond knurl on od surface, 5/32 in. lg by 45 deg chamfer on periphery of od on smallest id end, 0.166 in. dia hole, 90 deg countersink 1/32 in. deep located in centerline 0.400 in. from largest id end, 0.200 in. w unthd portion located on largest id end
Used on pza machine gun, grenade, 40mm mod iii(hild), mk19. 2b thread class right-hand 24 thread quantity per inch medium straight or diamond knurl on od phosphate surface treated
Used on sea stallion h-53 helicopter. 2a thread class right-hand 16 thread quantity per inch shoulder not stepped, four 0.040 in. dia lockwire holes drilled in flange end anodize surface treated
