Introduction of Common Mold Material

mold steel material pictureI can guess some of us may not be so familiar with those mold material that your supplier quoted. This is why I would like to share some common mold materials which used in the mold manufacturing industry.

First of all, let’s have a glance of the common mold material as:P20, 718, NAK80,S136, 738,SKD61. And then we can discuss one by one for their properties as below:


P20 is a famous Chinese local steel for the production of plastic mold and die casting. As P20 steel has good machinability and mirror grinding performance. It can be directly used for mold processing, and has the characteristics of good dimensional stability, pre-hardened steel to meet the general needs of the mold life of 500,000 cycles.


The material of 718 is very similar to the P20, but 718 is more competitive because of its better hardenability, superior performance, you can make large size, high-grade plastic mold parts. With the development of plastic mold, there will be more and better updated to improve the mold steel appears, 718 is commonly used in the manufacture of TV chassis, washing machine, refrigerator shell, bucket and so on. On the other hand, 718 is widely used in die casting mold and blowing mold. Especially 718 can be used for mirror polish mold in application of plastic mold of PA、POM、PS、PE、PP、ABS, and it’s mold life can meet 800,000 cycles.


NAK80 is a high quality mold steel manufactured by Japan for its excellent hardness of HRC37~43, what’s more NAK80 is friendly to polish, EDM,and machining.NAK80 can meet European and US clients’ requirement, it’s widely used for automotive parts mold, printer plastic parts, and other high quality plastic parts. Normally NAK80 can meet a mold life for at least 500,000 cycles.


S136 is an economical mold material in the mold industry. But it reach a great maintenance property as S136 can be stocked in normal work condition for a long time, never get rusty

S136 mechanical characteristic:

  • excellent corrosion resistance
  • excellent throwing optical rotation
  • excellent wear resistance
  • excellent machinability
  • quenching with excellent stability


738 is a pre-hardened plastic mold steel from Buderus in Germany, for 738 perform a hardness standards 29 ~ 33HRC 738 . As a result of the addition of nickel, to improve its hardenability, large cross-section thick plate hardness distribution. Mainly used in large-scale plastic mold, mold, such as car bumpers, TV shell mold, and so on. (PS) and ultra-non-quenching (ABS), etc.

738 steel Features: Excellent processing performance, easy cutting and polishing and electric erosion. 738 steel by adding nickel components, hardness uniformity, with excellent processing performance and polishing performance. Mainly used in high-demand plastic mold, suitable for televisions, fax machines, home appliances plastic parts, auto parts and other requirements of a certain polished plastic mold. The following are the same as the ”

738H German plastic mold steel 738H is based on the 738 plus hardening improved, the steel by adding nickel components, hardness uniformity, with excellent processing performance and polishing performance


SKD61 is a Japanese brand of hot work die steel, it is the most widely used hot work die steel, SKD61 is similar to the US mold steel H13, and equal to South Korea STD61

SKD61 mold steel is consist of silicon, chromium, molybdenum, vanadium medium alloy hot work die steel quenched, tempered after the organization of fine, fine grain of martensite, basically distributed with small carbon, with Good comprehensive mechanical properties, and good hardenability, more suitable for manufacturing large size, complex shape of the mold.

High temperature strength and toughness, good wear resistance, easy cutting; 2, SKD61 is a very good strength, toughness and heat resistance of the thermal die steel, in recent years with the development of isotropic products and increasingly High toughness and other aspects of development, it can make the mold life longer, more stable performance, and easy processing, heat treatment deformation small.

SKD61 is the most widely used in aluminum and zinc die-casting mold materials. It is made of high temperature resistant alloy steel containing tungsten component. It is suitable for hot work, aluminum, magnesium, zinc, copper alloy die-casting mold, cutting knife, scissors and heat Forging action, plastic mold, hot reamer, rolling knife, general hot forging die, hot bolt mold, hot various tools.