A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5930-01-643-2767
NSN 5915-01-196-6016
NSN 5950-00-367-2705
NSN 5965-01-480-3096
NSN 7035-00-104-7613
NSN 5960-00-860-7709
NSN 6135-00-295-2614
NSN 6650-00-434-0188
NSN 5950-01-155-0880
NSN 5985-01-433-5228
NSN 5925-01-406-5626
NSN 6150-01-419-0386