Die casting molds, also known as punch dies, are typically made from high-quality tool steel. Specific types of tool steel used for die casting molds include:

1. H13 tool steel: H13 is a hot work tool steel that is commonly used in die-casting molds due to its excellent combination of high toughness, heat resistance and wear resistance. It can withstand the high temperatures and thermal cycles associated with the die-casting process.

2. P20 Tool Steel: P20 is a general purpose mold steel typically used in low-volume die casting applications. It has good machinability, polishability and dimensional stability.

3. D2 tool steel: D2 is a high-carbon, high-chromium tool steel used for die-casting molds that require high wear resistance and good toughness.

These tool steels are selected for die casting molds because they can withstand the high pressures, temperatures and repeated cycles of the die casting process while maintaining dimensional stability and wear resistance. Additionally, they can be machined and polished to create the complex shapes and fine surface finishes required for die casting molds.