A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5945-01-184-8811
NSN 6610-00-990-9825
NSN 5895-00-753-5349
NSN 5935-00-768-7310
NSN 5990-01-254-3197
NSN 5996-01-564-6864
NSN 5945-00-628-5937
NSN 5930-01-004-7894
NSN 5835-01-248-0563
NSN 5855-01-068-3683
NSN 5925-01-081-7253
NSN 5998-01-624-2652