A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6145-01-205-5184
NSN 6145-00-607-8810
NSN 5915-01-445-6577
NSN 5999-01-394-9034
NSN 5915-00-196-7016
NSN 6220-01-338-7123
NSN 5945-01-343-4902
NSN 6685-00-359-5569
NSN 4140-01-361-8883
NSN 5915-01-131-2763
NSN 6105-00-352-9481
NSN 5998-01-165-8897