A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6145-01-634-0388
NSN 5999-00-957-6548
NSN 6320-01-512-2031
NSN 2925-01-364-7926
NSN 5998-00-081-1299
NSN 5920-00-665-3973
NSN 5930-01-525-8279
NSN 6610-01-023-6073
NSN 5998-00-937-4309
NSN 5999-00-542-0541
NSN 5855-00-610-4052
NSN 5905-01-361-6531