A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6130-01-451-8768
NSN 5960-01-263-3407
NSN 5905-01-331-2783
NSN 6320-00-788-5297
NSN 4140-01-370-1309
NSN 6610-00-469-8534
NSN 6220-00-183-4066
NSN 5975-01-360-5583
NSN 5990-00-011-2994
NSN 5950-01-281-5079
NSN 5935-01-310-5740
NSN 6220-00-357-1933