A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5935-00-079-5336
NSN 5930-01-194-5767
NSN 4140-00-442-3227
NSN 2925-01-156-9570
NSN 6130-01-435-6140
NSN 5855-01-441-1392
NSN 5855-01-441-3189
NSN 6645-01-220-2838
NSN 5835-01-147-7526
NSN 5999-01-470-5559
NSN 5895-00-198-5537
NSN 5935-01-090-4206