A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5950-00-795-9862
NSN 6620-01-545-7396
NSN 5965-01-580-0938
NSN 5915-00-502-5173
NSN 6685-00-829-2797
NSN 6610-01-604-1744
NSN 5925-00-152-7705
NSN 6240-01-500-1714
NSN 5960-01-498-0572
NSN 2925-01-282-3206
NSN 5965-01-271-9990
NSN 6650-01-607-6888