A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6650-01-579-7240
NSN 6145-01-497-9292
NSN 5998-00-500-8551
NSN 5950-01-106-1733
NSN 6130-01-291-6272
NSN 5925-00-494-4685
NSN 5935-00-931-0092
NSN 5998-01-645-6329
NSN 5935-01-290-5308
NSN 5835-01-071-2814
NSN 4140-00-884-4553
NSN 5999-00-942-3848