A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5975-00-553-7151
NSN 7035-01-612-8091
NSN 5990-00-931-6304
NSN 5965-00-407-4828
NSN 5945-01-204-6920
NSN 5935-01-557-9669
NSN 6610-00-468-1958
NSN 5835-01-399-5820
NSN 6685-01-332-7822
NSN 6320-01-624-0193
NSN 6220-01-268-1541
NSN 5990-00-306-0222