A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 7035-00-205-8739
NSN 5998-01-194-8609
NSN 5985-01-423-8902
NSN 6145-01-432-1198
NSN 5930-01-422-1693
NSN 2925-00-542-8285
NSN 5930-00-754-3363
NSN 7035-01-013-0092
NSN 2925-01-480-8273
NSN 5960-01-122-2686
NSN 6135-01-653-1437
NSN 6110-01-354-1322