Mouth after mold and core assembly form the cavity of the duct flow in a molten material, molten material from here, due to the shrinking of the cavity volume under pressure, in the period of the mouth and core rod inside the cavity forming tube billet when it is squeezed. The inner diameter of the die is the dimension part of the outer diameter of the forming pipe.

Mouth die cast iron with copper alloy material, the main ingredients: copper, aluminum, nickel, casting hardness is 210-230 - hb, adopting secondary melting process, ensure the stability of the material, copper alloy mold material has good dimensional stability of thermal fatigue and high temperature performance, relatively cast iron mould service life 5 times, it is mainly used for opening mold, mold, molding die.