A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5925-00-782-1361
NSN 6105-01-401-5361
NSN 6650-00-938-9233
NSN 4140-01-460-0440
NSN 5910-01-107-7807
NSN 4140-01-653-9368
NSN 2925-01-391-9247
NSN 6135-00-405-1989
NSN 6150-01-521-3526
NSN 6150-00-429-2682
NSN 5905-01-252-8833
NSN 6150-01-281-3699