Introduction

In the world of plastic mould making, tool steel selection plays a crucial role in performance, cost efficiency, and the final product’s quality. Among the most widely used materials are P20 Tool Steel and P20S Tool Steel. Both are pre-hardened steels designed for mould manufacturing, yet they differ in machinability, polishing characteristics, and suitability for specific applications. 

In this article, we compare P20 vs P20S Tool Steel to help manufacturers, engineers, and procurement teams make the right choice. 

What is P20 Tool Steel? 

P20 Tool Steel is a versatile, pre-hardened mould steel known for its

• Hardness of 28–32 HRC (delivered in pre-hardened condition). 
• Excellent toughness and durability. 
• Good machinability for standard mould making. 
• Suitable for plastic injection moulds, extrusion dies, and die casting tools. 

Its balanced properties mamold-makingthe most preferred steels in the mould-making  industry. Learn more on our dedicated page: P20 Tool Steel.

What is P20S Tool Steel? 

P20S Tool Steel is a modified version of P20 with sulphur (S) added to the chemical  composition. This addition enhances machinability and allows faster cutting speeds,  making it highly popular for large-scale or complex moulds. 

Key characteristics of P20S: 

• Improved machinability compared to P20. 
• Good toughness and strength. 
• Slightly reduced polishability due to sulphur content. 
• Widely used in automotive moulds and large injection mould tools.

 Discover more: P20S Tool Steel. 

Chemical Composition Comparison 

 Difference: The presence of sulphur in P20S enhances machinability but reduces  polishability compared to P20. 

Mechanical Properties 

P20 Tool Steel: 

• Hardness: 28–32 HRC 
• Tensile Strength: ~1000 MPa 
• Excellent toughness and polishability 

P20S Tool Steel:

• Hardness: 28–32 HRC 
• Similar tensile strength, slightly lower toughness than P20 o Superior machinability, moderate polishability 

Key Differences Between P20 and P20S 

Applications in Mould Making 

P20 Tool Steel Applications: 

• High-gloss plastic injection moulds 
• Extrusion dies 
• Die casting tools 
• Compression moulds 

P20S Tool Steel Applications: 

• Automotive parts moulds 
• Large injection moulds 
• Mould bases requiring faster machining 
• General tooling where speed matters more than surface polish 

Equivalent Grades 

Both steels have close equivalents in international standards: 

P20 Tool Steel Equivalents:

• AISI: P20 
• DIN: 1.2311 / 1.2312 
• JIS: SKD61 

P20S Tool Steel Equivalents: 

• DIN: 1.2312 (Modified) 
• Similar to AISI P20 with sulphur modification 

For other tool steels, explore D2 Tool Steel and H13 Tool Steel listed in our Tool Steel  section. 

P20 vs P20S: Which Should You Choose? 

Choose P20 Tool Steel when:

• High surface finish and polishability are critical. 
• The mould requires excellent wear resistance and toughness. 
• Applications demand long tool life and high-quality finish. 

Choose P20S Tool Steel when:

• You need faster machining speeds to save production time. 
• The mould size is large, and machinability is more important than polish.
• Applications involve automotive and industrial tooling where surface finish is  secondary. 

Conclusion 

Both P20 and P20S Tool Steels are excellent choices for mould making, but the right  selection depends on application needs. P20 offers better polishability for high-gloss  finishes, while P20S provides faster machinability for large and complex moulds.