A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6105-01-317-3657
NSN 6110-01-474-4280
NSN 6610-01-441-1581
NSN 5910-00-564-6766
NSN 6135-00-112-8637
NSN 5960-01-416-6187
NSN 6645-01-400-1137
NSN 7035-01-580-0957
NSN 5915-00-056-2197
NSN 5905-00-389-6252
NSN 5925-01-419-6287
NSN 5925-01-502-2060