A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5945-00-058-0240
NSN 5920-00-857-5055
NSN 6135-00-877-1659
NSN 5985-01-347-3007
NSN 5985-01-003-9732
NSN 6105-00-816-9397
NSN 6650-00-954-4428
NSN 7035-01-564-9539
NSN 5855-01-178-6396
NSN 6240-01-522-0875
NSN 2925-00-478-3742
NSN 6105-01-532-8222