A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5975-01-580-7351
NSN 5895-00-270-0949
NSN 5998-00-785-4992
NSN 6610-01-623-6228
NSN 6130-01-004-8977
NSN 5915-01-437-1519
NSN 5915-01-300-6279
NSN 6130-01-546-0309
NSN 6150-00-100-4757
NSN 6685-01-406-5348
NSN 6150-01-613-8455
NSN 6650-01-092-8435