The Proxxon 24 piece Torx Socket Set is made from chrome vanadium steel (31 CrV 3). It is designed for use in industry or a professional workshop. It contains 1/4" drive TORX sockets in sizes TX8 to TX30 (with frontal hole) and external TORX sizes E4 to E8 (all suitable for tightening torques up to 10Nm). 1/2" drive TORX sockets in sizes TX40 - 60 and external TORX E10 to E18 (for tightening torques from 25 to 135Nm) plus three offset TORX wrenches; TX6, 8 and 10. The sturdy, welded steel box is powder coated for durability with a strong moulded plastic insert for the secure placement of each item.