A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 2925-00-886-4718
NSN 5960-01-141-3252
NSN 6135-00-628-1142
NSN 5895-00-467-1140
NSN 5950-01-211-1860
NSN 6130-01-366-7481
NSN 6240-01-188-7282
NSN 6150-01-427-3764
NSN 7035-01-440-1862
NSN 5915-00-969-6382
NSN 4140-01-407-6595
NSN 5985-00-359-9067