A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6240-01-384-4868
NSN 5975-01-193-8662
NSN 6110-01-205-0669
NSN 5985-01-634-0635
NSN 5920-00-946-9147
NSN 4140-01-501-2944
NSN 6220-01-317-8822
NSN 5998-01-431-8533
NSN 6645-01-307-8203
NSN 6135-01-599-7563
NSN 5915-00-688-2742
NSN 5930-01-175-1696