A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6645-00-269-2764
NSN 5920-01-321-3168
NSN 6685-01-141-9255
NSN 5998-01-145-7369
NSN 5930-01-123-9688
NSN 5905-01-441-1153
NSN 6685-00-148-8383
NSN 5945-01-313-2052
NSN 5905-01-286-2130
NSN 5895-01-474-5209
NSN 4140-00-947-3918
NSN 6105-01-367-2269