A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5945-01-477-8336
NSN 6320-01-346-5158
NSN 6240-00-952-4501
NSN 2925-01-011-8732
NSN 7035-00-557-5570
NSN 5935-01-007-6400
NSN 5895-01-089-5261
NSN 5960-00-960-6805
NSN 6650-00-945-9105
NSN 5999-01-301-1076
NSN 5960-00-942-0934
NSN 2925-01-629-9416