Manufactured from Chrome Molybdenum Alloy Steel with a black phosphate finish hardened and tempered these sockets withstand very high speed power tools. Each Spline bit is 80mm long giving you greater access too hard to reach places. Specifications: Chrome Molybdenum Alloy Steel. SCM440 HRC45. Black phosphate finish. DIN 3121. Hardened and tempered. True impact. 1/2" inch drive. Blow moulded case. Sizes: M5 M6 M8 M10 M12 M14 M16 M18.