A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5960-01-160-3437
NSN 2925-00-961-2117
NSN 5835-00-783-6620
NSN 5996-00-997-6366
NSN 5985-01-157-8894
NSN 6110-00-629-0284
NSN 7035-01-325-0536
NSN 5920-00-265-6222
NSN 7035-01-435-4009
NSN 5985-01-227-2220
NSN 6650-00-866-9947
NSN 5965-01-195-2168