A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6110-01-538-8835
NSN 5895-00-239-9138
NSN 6105-00-919-0017
NSN 5930-00-484-7576
NSN 4140-01-005-0154
NSN 5910-01-076-2310
NSN 5920-01-048-6907
NSN 5925-01-036-9421
NSN 5855-00-054-4686
NSN 4140-00-232-1039
NSN 6105-01-083-2186
NSN 6685-01-359-5732