A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5960-00-257-4203
NSN 5960-01-141-7584
NSN 5945-01-581-6298
NSN 6610-01-298-5662
NSN 4140-01-088-0401
NSN 5996-00-868-2543
NSN 5855-00-762-4833
NSN 6130-01-103-8480
NSN 6620-00-538-8746
NSN 6145-01-617-2234
NSN 4140-01-013-0795
NSN 6240-00-879-5830