What is plastic tool steel?

Plastic tool steel is a type of steel specifically used for manufacturing plastic molds. Its core characteristics are high hardness, high wear resistance, and good polishing performance to meet the precision requirements during the molding process of plastic products. According to the composition and process characteristics, plastic mold steel is mainly divided into the following categories:

Main Categories
Time hardening plastic mold steel
Hardness improvement is achieved through heat treatment, suitable for molds with high precision and high surface finish, such as mirror molds.
Pre hardened plastic mold steel
Pre hardened before leaving the factory, it can be directly processed to reduce the risk of heat treatment deformation and is commonly used in large molds or mold frames.
Corrosion resistant plastic mold steel
Adding chromium and other elements to enhance corrosion resistance, suitable for molds used in the production of acidic plastics such as PVC.
Carbonized plastic mold steel
Surface carburizing treatment is used to improve wear resistance and is suitable for molds with complex shapes.

Typical grades and performance
S136: High mirror finish, corrosion-resistant, suitable for transparent plastic product molds.
1.2316: Pre hardened state, balanced comprehensive performance, excellent corrosion resistance and polishing properties, widely used in injection molds for automobiles, household appliances, etc.
NAK80: Easy to cut, highly polished, suitable for precision electronic component molds.
P20: Universal pre hardened steel, low cost, used for general plastic product molds.

Application field
Plastic tool steel is mainly used in injection molds, blow molds, compression molds, etc., involving industries such as automotive, electronics, medical, and daily necessities. The selection should take into account the plastic type (such as corrosiveness, flowability), mold life, and cost factors.

Key factors in material selection
Plastic type: Corrosive plastic (such as PVC) requires corrosion-resistant steel; High fluidity plastics (such as PA) require materials with high wear resistance.
Mold lifespan: High hardness and wear-resistant materials (such as carburizing or age hardening) are required for mass production to extend the service life of the mold.
Cost control: Pre hardened steel can reduce subsequent processing costs, suitable for small and medium-sized production, and optimize overall economic benefits.

Key points of process and maintenance
Processing technology: Pre hardened steel can be directly processed, simplifying the process; Aging hardened steel needs to be roughly processed after solution treatment, followed by aging treatment to ensure stable performance.
Surface treatment: Mirror molds require fine polishing (such as electrolytic polishing) to improve the surface quality of the product; The carburizing mold needs to control the depth of the infiltration layer (usually 0.5-2mm) to balance wear resistance and toughness.
Maintenance suggestion: Regularly clean the surface of the mold to avoid corrosion from acidic residues; Apply anti rust oil during storage to prevent oxidation damage and extend the lifespan of the mold.

Through rational material selection and process optimization, plastic tool steel can significantly improve mold life (up to millions of times) and product yield, reduce comprehensive production costs, and provide efficient and reliable solutions for the plastic products industry.