A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5999-01-583-0439
NSN 5975-01-329-1268
NSN 5920-01-239-2038
NSN 5895-01-593-6001
NSN 6650-01-055-6168
NSN 5925-01-212-5707
NSN 6105-00-828-9230
NSN 2925-01-386-7392
NSN 5835-01-566-5462
NSN 6645-01-578-6815
NSN 6110-01-526-5562
NSN 5998-01-364-4267