Made of 45# high carbon steel, quenched and forged body, with high hardness, good toughness and easy to rotate.Hardness can be up to HRC 48-52. Large wrench is 14.76”/375mm in length, small wrench 10.43”/265mm;Capacity: 1.2”-2.4” (L) and 0.6”-1.2”(S), it can use on pipe,screw,nut and so on.