A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5990-01-143-2518
NSN 5996-00-226-5364
NSN 6620-00-546-6071
NSN 5855-01-491-4623
NSN 6145-01-224-6000
NSN 6105-00-370-0261
NSN 5930-00-423-7145
NSN 5855-01-049-5354
NSN 6610-00-880-5204
NSN 5990-01-034-8211
NSN 5990-01-386-3040
NSN 5895-00-692-2912