A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5895-00-424-6296
NSN 6240-01-180-3720
NSN 5990-01-563-1554
NSN 6240-01-089-3827
NSN 6320-01-441-2438
NSN 2925-00-225-5386
NSN 6610-01-250-2811
NSN 5930-00-578-4266
NSN 6650-01-270-4512
NSN 5950-01-634-0677
NSN 5835-00-454-7239
NSN 6110-01-444-1688