A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5930-01-011-6298
NSN 5975-00-401-9913
NSN 6610-01-567-2765
NSN 5990-00-881-6624
NSN 6220-00-426-6340
NSN 5915-01-550-9703
NSN 4140-00-408-9989
NSN 5975-01-250-2940
NSN 6145-01-059-4910
NSN 6650-00-925-1274
NSN 5996-01-059-9552
NSN 5915-00-288-0071