Since the 70 s, the world has put forward the idea of pre hardened, but because of machine tools and cutting tools, stiffness of the pre hardened hardness can not meet the use of mold hardness, so in the process of the hardening technology r&d. Along with the improvement of the performance of the machine tools and cutting tools, mold material hardening technology development speed, to the 80 s, the international industrial developed countries in plastic mould materials using the proportion of the pre hardened module has reached to 30% (currently at more than 60%).