A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6145-01-241-0965
NSN 5920-01-513-8848
NSN 6145-00-370-1964
NSN 6620-01-412-0938
NSN 6145-00-347-1171
NSN 2925-01-421-9665
NSN 6240-00-437-5216
NSN 7035-00-117-0418
NSN 5965-01-573-9229
NSN 6110-01-391-7542
NSN 6645-01-582-9833
NSN 6610-01-605-1509