A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5999-01-494-3052
NSN 6650-00-232-6390
NSN 5925-01-101-1857
NSN 5975-01-437-3136
NSN 4140-00-107-8212
NSN 5855-00-879-7245
NSN 6320-00-831-2227
NSN 5915-01-239-8931
NSN 5920-01-416-2518
NSN 6130-01-440-6527
NSN 5999-01-039-4185
NSN 5925-01-604-4008