A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 7035-01-509-1959
NSN 6685-01-139-0270
NSN 5990-01-644-3095
NSN 2925-01-253-6006
NSN 6685-01-426-8929
NSN 5835-01-457-7951
NSN 7035-01-116-6223
NSN 5920-01-626-8736
NSN 5935-01-587-9183
NSN 5855-01-175-2465
NSN 6650-00-466-1697
NSN 5895-01-319-9151