A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5915-00-577-9024
NSN 6135-00-782-6988
NSN 7035-01-438-2108
NSN 5935-01-189-4345
NSN 6685-00-972-5886
NSN 5905-00-583-7150
NSN 6610-00-171-5015
NSN 6650-01-540-5157
NSN 5930-01-134-2832
NSN 5975-01-443-3160
NSN 5895-00-165-6598
NSN 6130-01-560-8284