A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6130-00-276-0658
NSN 5985-00-493-6652
NSN 6105-01-325-0110
NSN 5915-00-628-8960
NSN 6135-01-132-6310
NSN 5925-01-112-8473
NSN 5930-01-546-2999
NSN 6105-01-201-4311
NSN 2925-00-245-4440
NSN 6130-00-251-9156
NSN 6145-00-553-8196
NSN 6620-01-471-8128