A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 7035-01-441-8363
NSN 7035-01-241-2127
NSN 6320-01-493-4472
NSN 5998-01-290-3733
NSN 6105-01-564-4952
NSN 6105-00-111-0851
NSN 6650-01-433-1911
NSN 6150-00-467-0803
NSN 6240-01-304-6355
NSN 5999-00-558-7305
NSN 5975-01-075-3393
NSN 5930-00-729-3768