A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5895-00-089-9375
NSN 6130-01-533-2833
NSN 5935-01-224-1180
NSN 6240-00-617-1818
NSN 5985-01-414-5120
NSN 5920-01-204-6419
NSN 6105-01-171-0271
NSN 5895-01-027-1192
NSN 6135-01-390-7364
NSN 5945-01-455-4883
NSN 5920-01-209-5187
NSN 6130-01-041-4615