A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5996-00-931-2500
NSN 5960-01-310-3863
NSN 5945-00-081-7488
NSN 6150-01-051-6489
NSN 6320-01-064-0372
NSN 5945-01-557-6405
NSN 5999-01-389-4138
NSN 6610-01-327-3187
NSN 5895-00-276-7916
NSN 5925-00-496-3826
NSN 5920-01-329-4571
NSN 5930-00-691-1348