In order to obtain high surface hardness and wear resistance, many stamping die and stamping die accessories have to carry out surface heat treatment, such as surface nitriding. For such a mold people are very concerned about its surface hardness and hardened layer depth.

In order to obtain high surface hardness and wear resistance, many stamping die and stamping die accessories have to carry out surface heat treatment, such as surface nitriding. For such a mold people are very concerned about its surface hardness and hardened layer depth.


There is an error worth correcting when testing the hardness of surface heat treated stamping die steel. This is the inappropriate use of the Richter hardness tester for such an occasion. This is determined by the principle of the Richter hardness tester. Cloth, lowe, d three commonly used hardness tester are static testing principle, is a hard head slowly pressed into the sample surface, and then test indentation depth or size, determine the size of the hardness value. The Richter hardness tester uses dynamic testing principle. It is a specified mass of the sphere with a specified speed impact sample surface, test its initial speed and rebound speed difference, in order to determine the hardness value of the sample. To understand this, just look at how thick the standard Hardness blocks on the Richter scale are. It clearly didn't measure the hardness of the nitride layer.

Hardness is not the hardness of the base material, but the result of the joint action of the two, because of the different thickness of the surface layer of the stamping parts, it is bound to get different results.

The main material of stamping die is die steel (including tool steel and high speed steel), and sometimes hard alloy stamping die is usually required to have high hardness and wear resistance, heat treatment is essential.