•Manual welding, the wrench welding place is manual welding, which is strong and durable, and has a hexagonal design at the root .The outer hexagonal design at the root of the socket head can be applied to spanner tools, and the spanner is heat treated as a whole High-frequency quenching, fine polished chrome-plated surface, durable and beautiful.2.The carbon content is as high as 0.60% to 1.70%, the hardness is higher, and the hardness is strengthened after heat treatment, high-frequency quenching, the surface is polished and chrome-plated, durable, beautiful, and the root is external hexagonal design .Specification: Product Name: Triangular Socket Wrench Material: Chrome vanadium alloy steel System: Metric Size:8-9-10mm,8-10-12mm,10-12-14mm,11-13-15mm,12-14-17mm,14-17-19mm(optional)Type:3 Way