Since it is to be used to make tooling heat treatment, then the choice of natural materials to meet some basic requirements of the heat treatment, and then select a performance on the basis of the best heat treatment such tooling is also made to achieve a higher standard.

The first point is the material requirements to facilitate the lifting and handling to meet the heating and cooling of the workpiece, and thus serve to prevent or mitigate the distortion effect. In addition, the production of heat-treated tooling material characteristics but also can withstand repeated use, on this basis, to ensure that no deformation, the long service life.
On the above two points, the real matching material is not much, there are gray cast iron, carbon and crystal structure at room temperature for the α-Fe, the body-centered cubic lattice, organizations ferrite pearlite or martensite concentrated. But they are not all suitable for the production of tooling heat treatment, wherein the best and most practical or 1Cr18Ni9Ti, because the phase transition point of this material is low, after heating and cooling until room temperature will have a phase transition, the crystal structure will not change .