A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5975-01-208-7002
NSN 2925-01-206-2250
NSN 5945-01-418-2185
NSN 6135-00-432-8779
NSN 6220-00-119-1507
NSN 5895-01-578-6623
NSN 5920-01-413-5266
NSN 6320-00-456-2092
NSN 5920-00-844-2488
NSN 5950-01-399-8677
NSN 6130-01-190-3332
NSN 6130-01-486-3574