Fortum (4700901) Spark plug socket, 1/2", 21 mm, L 65 mm, 61CrV5

Drive Socket - greater durability. Fortum socket wrenches are cast from 61CrV5 chrome-vanadium steel and treated on NCS machines, hardened in oil and tempered around the perimeter to achieve optimum hardness and strength in thin-walled construction, 61CrV5 and 61CrV4 (designated both 6150 and 6140) being the highest grade of chrome-vanadium steel. Hardened and coated with matt hard chrome for optimum surface hardness and corrosion resistance, this steel is used for all but the most exposed parts TECHNICAL PARAMETERS - 21 mm, L 65 mm