A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5835-00-334-6556
NSN 5915-00-281-8175
NSN 5935-00-468-0938
NSN 5905-01-247-3324
NSN 5998-01-648-9734
NSN 6110-00-866-6140
NSN 7035-01-271-1643
NSN 5925-01-535-4409
NSN 6150-00-150-8838
NSN 6610-00-341-7549
NSN 5960-01-195-6440
NSN 5999-01-607-4605