A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5965-01-323-7225
NSN 5998-01-083-2717
NSN 5990-00-389-0554
NSN 6620-01-368-2723
NSN 6130-01-248-8614
NSN 5895-01-510-4836
NSN 5915-00-018-1282
NSN 5999-01-525-7937
NSN 5996-01-611-6495
NSN 6220-01-555-8332
NSN 6645-01-315-2010
NSN 5915-01-610-5168