A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5855-00-361-0167
NSN 2925-00-193-2402
NSN 5985-01-642-5395
NSN 2925-01-251-5725
NSN 5925-01-422-6783
NSN 4140-01-443-9164
NSN 5935-01-034-1117
NSN 2925-01-569-5471
NSN 5920-01-522-7318
NSN 6110-00-937-5800
NSN 6110-01-068-4998
NSN 5975-01-288-1059