A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6110-01-289-7961
NSN 5975-01-063-8017
NSN 6320-01-358-0141
NSN 6130-01-100-3285
NSN 6105-00-498-6731
NSN 6110-01-546-3680
NSN 5920-00-263-2192
NSN 6220-00-995-2837
NSN 6650-00-870-3226
NSN 6650-01-145-5663
NSN 7035-00-763-6180
NSN 6240-01-420-6495