A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5915-00-752-4458
NSN 5950-01-433-1853
NSN 5930-01-196-6917
NSN 6135-01-054-2098
NSN 6135-01-111-1495
NSN 5945-01-055-4305
NSN 7035-00-834-2090
NSN 6130-01-468-6484
NSN 4140-01-283-1275
NSN 5930-01-368-5190
NSN 6150-01-065-1023
NSN 5960-00-086-8764