The mold platen has a hardness of 55-58 HRC, while the frame has a hardness of 58-62 HRC. Why is the hardness of the platen lower than that of the mold frame?

A:Because if the hardness is the same, wear will occur simultaneously. The pressure plate has lower hardness, which can protect the mold frame. The cost of replacing the pressure plate is also lower. In addition, after a period of use, the inner cavity size of the mold frame will increase, so a larger pressure plate can be made when replacing the pressure plate to eliminate burrs.