A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5930-01-398-9576
NSN 6130-00-471-1868
NSN 6650-00-276-9838
NSN 6220-00-055-9917
NSN 6320-01-384-3850
NSN 6110-01-579-2344
NSN 6620-01-476-7355
NSN 6220-00-988-3230
NSN 5920-01-392-6383
NSN 6150-00-157-3126
NSN 5999-01-248-1247
NSN 6130-00-837-6902