A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6135-01-522-2463
NSN 6220-01-634-0660
NSN 6105-01-368-7864
NSN 5965-00-215-5866
NSN 6130-01-455-7828
NSN 5945-00-043-2093
NSN 5935-00-341-6290
NSN 5925-01-347-5807
NSN 2925-01-187-5480
NSN 6610-01-294-5666
NSN 2925-00-899-4261
NSN 5915-01-200-6338