A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 2925-01-222-7764
NSN 6320-00-646-3311
NSN 6145-01-486-0457
NSN 2925-01-545-2717
NSN 5985-01-380-0069
NSN 5910-01-606-7724
NSN 5945-00-196-2965
NSN 5855-00-145-3307
NSN 5985-00-116-8450
NSN 5855-00-125-0780
NSN 5915-00-254-3436
NSN 6110-01-037-9177