A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5945-00-189-8783
NSN 6650-01-209-6318
NSN 6220-00-229-6785
NSN 7035-00-111-4389
NSN 5996-01-633-7979
NSN 5999-01-364-2939
NSN 5835-00-165-3069
NSN 5945-01-354-9835
NSN 6105-01-467-7002
NSN 5835-01-387-4227
NSN 5996-00-960-7810
NSN 5960-00-452-6043