A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6110-00-901-3481
NSN 6150-00-419-0505
NSN 5998-00-779-3400
NSN 6130-01-596-7910
NSN 5835-00-195-7508
NSN 4140-00-200-0970
NSN 5910-00-422-3784
NSN 6105-01-285-1887
NSN 6220-00-366-1670
NSN 5985-00-270-6936
NSN 5855-00-281-3843
NSN 6150-00-725-5155