A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 4140-01-015-5137
NSN 6110-01-255-9892
NSN 5835-01-257-0154
NSN 6645-01-352-5675
NSN 5965-01-238-9287
NSN 6110-01-155-7004
NSN 5996-01-449-8184
NSN 6685-01-658-5057
NSN 6685-01-579-3636
NSN 5920-01-490-2733
NSN 5855-01-432-2487
NSN 5835-00-313-7197