A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5920-01-280-2168
NSN 5960-00-816-9040
NSN 5930-01-525-7665
NSN 6105-01-486-3600
NSN 5895-01-377-4613
NSN 2925-01-243-0328
NSN 5935-00-298-2004
NSN 5855-00-149-0766
NSN 6135-00-100-8890
NSN 2925-01-330-2988
NSN 6610-01-439-5447
NSN 6240-01-311-8058