A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 2925-00-024-6392
NSN 6240-01-184-6831
NSN 5915-00-466-2840
NSN 5985-01-238-6036
NSN 6320-01-495-0512
NSN 6135-00-377-9165
NSN 6320-01-629-1277
NSN 6150-00-738-9837
NSN 5925-01-101-7263
NSN 5985-00-563-7685
NSN 5985-00-248-4978
NSN 5990-01-270-3209