The key is that the section size of the fixture must meet the bearing requirements of the workpiece in the hot state.
Because the strength of general steel will decrease regardless of heat treatment at 450-500℃, it is necessary to consider the bearing capacity of tooling in hot state.
After tempering and heating below 500℃, the structure of the die matrix remains unchanged, but the strength changes with the increase of temperature.
If there is a problem with increasing the section size of 45 steel, we have to use cast iron tooling, and the deformation of the casting is very small; But the castings are both benzene and heavy.