A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5915-01-320-2528
NSN 5935-00-842-9974
NSN 6610-01-500-4181
NSN 5998-01-445-9874
NSN 5950-00-431-5118
NSN 6685-00-455-9941
NSN 4140-01-438-3854
NSN 5855-01-548-1555
NSN 6220-01-533-1302
NSN 5950-01-112-1172
NSN 5975-00-102-9639
NSN 5855-01-550-5219