A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6130-00-466-9888
NSN 5975-01-432-0640
NSN 5910-00-221-7750
NSN 6130-01-485-9090
NSN 5915-00-383-1471
NSN 5975-01-444-7942
NSN 5855-00-925-0114
NSN 5925-00-225-1831
NSN 6620-01-575-9561
NSN 5905-01-583-1179
NSN 5999-01-586-9653
NSN 5935-01-282-0061