A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5999-00-055-5146
NSN 5999-01-546-0719
NSN 5835-01-337-8635
NSN 5935-01-403-2844
NSN 5960-01-077-6062
NSN 5985-01-206-4729
NSN 6130-01-555-8361
NSN 5945-01-066-2285
NSN 6150-00-498-3759
NSN 5945-00-203-1295
NSN 5920-01-187-3720
NSN 6150-01-147-4508