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1.2311 vs 1.2312 vs 1.2738 Plastic Mold Steel Differences

Plastic mold steel is a pearlitic steel grade based on Cr-Ni-Mo, and it is also one of the important materials in the mold manufacturing industry. Among them, 1.2311, 1.2312 and 1.2738 steel are the most commonly used materials. Although they are all plastic mold steels, there are certain differences. This article will discuss the differences between 1.2311, 1.2312, and 1.2738 plastic mold steel from several aspects, so as to help more customers buy suitable steel and better apply it to projects.

1.2311 vs 1.2312 vs 1.2738 Plastic Mold Steel Supply

1.2311 vs 1.2312 vs 1.2738 Steel Chemical Composition

DIN 1.2311 plastic mold steel

1.2311 steel is a high strength pre-hardened steel with low carbon content, also widely known as P20. Its chemical composition is as follows:

GradeC (%) Si (%) Mn (%)P (%)S (%)Cr (%)Mo (%)Ni (%)

DIN 1.2312 plastic mold steel

Compared with other plastic mold steels, 1.2312 steel is the steel with the highest sulfur content, and is also widely known as P20+S steel. Its chemical composition is as follows:

GradeC (%) Si (%) Mn (%)P (%)S (%)Cr (%)Mo (%)Ni (%)

DIN 1.2738 plastic mold steel

1.2738 steel is an upgraded material based on 1.2311 with nickel added, and is also widely known as P20+Ni steel. Its chemical composition is as follows:

GradeC (%) Si (%) Mn (%)P (%)S (%)Cr (%)Mo (%)Ni (%)

From the chemical composition of the above three steels, it can be seen that 1.2312 steel is significantly different from the other two steels in terms of silicon and sulfur elements; 1.2311 steel is similar to 1.2738 steel in chemical composition, only the nickel element is different.

Plastic Mold Steel Properties

The difference in chemical composition of 1.2311 vs 1.2312 vs 1.2738 plastic mold steel has a key impact on its performance, so there is a little difference in performance among the three.

  • 1.2311 steel: Reducing Mo and increasing Mn content, Mn can improve its strength, achieve good results, and reduce costs. It also has good wear resistance, hardness uniformity, etc., which can ensure the consistency and stability of mold manufacturing.
  • 1.2312 steel has more sulfur content, which makes it have excellent machinability, which is convenient for forming, processing and adjustment when making plastic molds. And after quenching and tempering, it has high toughness and impact toughness, and can withstand large dynamic loads and impact loads.
  • 1.2738 steel contains nickel element, which has higher hardness, better wear resistance, and toughness than 1.2311 and 1.2312 steel. It is less prone to wear and deformation during use, and its polishing degree is better than 1.2311, making it an ideal material for molds that require high-precision and smooth surfaces. Usually, its hardness range is between 32-36HRC. It also has higher durability, making it suitable for producing long-life molds or molds for producing large quantities of plastic products.

Mold Steel Application

(1) 1.2311 steel is usually used to make small and medium-sized molds.

(2) 1.2312 steel is suitable for the manufacture of molds with complex shapes, high precision and cutting performance requirements, especially parts that require complex processing.

(3) 1.2738 steel is used to manufacture large-scale, complex and high-load molds that resist impact, extrusion, wear, etc., and is especially suitable for the manufacture of molds that are required to be used at higher temperatures.

In terms of chemical composition, performance and application, 1.2311, 1.2312 and 1.2738 plastic mold steels have unique advantages and differences. In addition to the differences in these aspects, there are also differences in the production process. So if you want to buy plastic mold steel, understanding the differences between them can allow you to make the best choice and find the most suitable steel.


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