A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6220-00-334-7008
NSN 2925-01-144-7106
NSN 6620-01-504-5756
NSN 5930-00-674-4819
NSN 5925-00-024-0864
NSN 5965-01-135-3679
NSN 6145-01-196-0496
NSN 6145-01-491-6785
NSN 6110-01-209-2960
NSN 6110-00-809-1401
NSN 5935-00-584-4584
NSN 6145-01-436-6241