A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6145-01-548-2967
NSN 6610-00-614-1703
NSN 5996-01-343-2962
NSN 7035-01-380-6538
NSN 6105-01-158-2232
NSN 2925-01-027-1293
NSN 6105-01-106-4649
NSN 5996-01-621-3207
NSN 6145-01-212-7722
NSN 5835-01-312-4446
NSN 6145-00-929-4205
NSN 6620-01-397-8683