1. Forming method. Choose from two basic material types.
(1) Hot working tool steel that can withstand relatively high temperatures during die casting, forging and extrusion.
(2) Cold-worked tool steel for blanking and shearing, cold forming, cold extrusion, cold forging and powder press forming.
2. Plastic. Some plastics produce corrosive by-products such as PVC plastic.
Condensation, corrosive gases, acids, cooling/heating, water or storage conditions caused by prolonged shutdowns can also cause corrosion. In these cases, it is recommended to use a stainless steel die steel.
3. Mold size. Pre-hardened steel is often used for large size molds. Integral hardened steel is often used in small size molds.
The number of times the mold is used. Long-term use (>1000000 times) of the mold should use high hardness steel, the hardness of 48-65HRC. For medium long-term use (100,000 to 1,000,000 times), pre-hardened steel should be used, and its hardness is 30-45HRC. For short-term use (<100000 times), the mold should be made of mild steel with a hardness of 160-250HB.
4. Surface roughness. Many plastic mold manufacturers are interested in good surface roughness.
When sulfur is added to improve metal cutting performance, the surface quality is thus degraded. Steels with high sulfur content also become more brittle.