A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 2925-01-201-3043
NSN 5925-00-833-8291
NSN 6110-01-633-9660
NSN 6145-01-068-4668
NSN 6685-01-426-8929
NSN 7035-01-232-7263
NSN 6220-01-259-9816
NSN 6110-00-137-2348
NSN 5915-01-573-8221
NSN 5990-01-365-6016
NSN 5855-01-461-2741
NSN 5925-01-319-2434