1.steel mandrel 2.forged and annealed 3.ESR,EAF,LF+VD+EAF ... in many field.4Cr5MoSiV1 is common international hot die steel mold, the steel has excellent toughness and good heat resisitence, thermal ... die casting die, hot extrusion die, perforated using tools, a mandrel, forging die, plastic mould and so on, also widely ... cooperation will bring considerable profits to you.Thank you!!! h13 steel mandrel