A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6320-01-521-1764
NSN 5999-01-657-9079
NSN 5999-00-844-2073
NSN 5999-01-126-4966
NSN 5945-00-560-0406
NSN 5996-01-596-7836
NSN 5935-00-727-5270
NSN 5985-01-528-7050
NSN 6320-01-426-8947
NSN 5998-01-323-2259
NSN 2925-01-113-6904
NSN 5910-01-283-3041