What is the most important and most decisive factor in selecting tool steels?

- Mar 13, 2018-

Forming Method - Choose from two basic material types. 

           A) Hot work tool steel, which can withstand relatively high temperatures during die casting, forging and extrusion. 

           B) Cold-work tool steels, which are used for blanking and shearing, cold forming, cold extrusion, cold forging and powder press forming. 

          Plastics - Some plastics produce corrosive byproducts such as PVC plastic. Factors such as condensation, corrosive gases, acids, cooling/heating, water, or storage conditions caused by prolonged shutdown can also cause corrosion. In these cases, stainless steel mold steel is recommended. 

           Mold size - Large size molds often use pre-hardened steel. Integral hardened steel is often used for small size molds. 

           Mold usage times - long-term use (> 1000000 times) of the mold should use high hardness steel hardness of 48-65HRC. Medium and long-term use (100000 to 1000000 times) of the mold should use pre-hardened steel, its hardness is 30-45HRC. Mild steel should be used for short-time (< 100000) molds and its hardness is 160-250 HB.

         Surface Roughness - Many plastic mold makers are interested in good surface finish. When sulfur is added to improve metal cutting performance, the surface quality is reduced. Steels with high sulfur content also become more brittle.