A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5985-01-400-1968
NSN 5905-00-584-5009
NSN 6240-00-698-5822
NSN 4140-00-815-7093
NSN 5985-01-388-1273
NSN 6620-00-634-9455
NSN 5985-00-831-0202
NSN 5915-01-468-8034
NSN 6130-01-306-3365
NSN 5935-01-471-5969
NSN 5998-01-548-5594
NSN 6130-01-432-6831