A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6150-01-329-9828
NSN 6650-01-003-6467
NSN 6110-01-627-3971
NSN 6320-01-498-4954
NSN 6685-01-452-9483
NSN 5915-00-525-5753
NSN 2925-01-656-0392
NSN 5925-00-681-1044
NSN 6110-00-752-2757
NSN 6320-01-283-9370
NSN 6105-01-534-3378
NSN 5835-01-619-6270