A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5996-01-357-1967
NSN 6220-01-437-7667
NSN 5950-01-216-3639
NSN 6685-01-143-2704
NSN 5930-01-455-6474
NSN 6240-00-069-8038
NSN 6650-00-473-1259
NSN 6610-01-574-9829
NSN 5835-00-729-9305
NSN 5910-01-580-0857
NSN 5910-01-381-3009
NSN 5935-01-569-8082