A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5990-00-150-6979
NSN 5985-00-498-1554
NSN 5945-01-508-9075
NSN 2925-01-653-6394
NSN 6620-01-476-7355
NSN 6150-01-246-3339
NSN 5895-01-160-4407
NSN 5905-01-450-9672
NSN 2925-01-250-2731
NSN 5895-01-167-7656
NSN 6320-01-328-6575
NSN 5920-00-177-2738