P20 Mould Steel 3Cr2Mo 1.2311
P20 mould steel is a general-purpose pre-hardened plastic mould steel with good machinability, polishing performance, weldability, and balanced strength and toughness. It is widely used for plastic molds, mold bases, automotive interior molds, home appliance molds, and other tooling applications that require reliable performance, stable hardness, and cost-effective service life without additional heat treatment.
Product Description
Xiri Tool Steel is a leading supplier of AISI P20 mould steel (DIN 1.2311) in China. P20 mold steel is a general-purpose pre-hardened plastic mold steel. The hardness at factory production is approximately 30-36 HRC. It has good cutting machinability, polishing performance and weldability. It is commonly used to manufacture plastic molds for household appliances, automotive interior parts, etc. with moderate requirements. Its price is relatively low, but its corrosion resistance and mirror-polishing ability are relatively weak. It is not suitable for molds for transparent or highly polished products.
Whether you need P20 flat bars, 1.2311 steel plates, or forged rounds, we provide custom dimensions with machining or grinding services. Our materials are strictly tested to ensure premium metallurgical structure.
P20 mould steel is a medium-carbon alloy tool steel widely employed in plastic mould manufacturing. It is renowned within the industry for its exceptional balance – offering excellent machinability, good strength and toughness, moderate wear resistance, and the characteristic of being pre-hardened at the factory. Simply put, P20 is a versatile material engineered to tackle the complex challenges of plastic production, serving as a dependable choice for crafting cost-effective, long-lasting moulds.
Chemical Composition of DIN 1.2311 / AISI P20 mould steel
| C | Si | Mn | Cr | P | S | Mo |
| 0.35-0.45 | 0.20-0.40 | 1.30-1.60 | 1.80-2.10 | ≤0.030 | ≤0.035 | 0.15-0.25 |
Supply Form & Size Range of 1.2311 / AISI P20 mould steel
We supply 1.2311 / P20 steel in various forms to meet your manufacturing needs:
Round bar: Diameter 16mm – 1200mm
Steel Plate / Flat: Thickness 16mm – 1000mm x Width 200mm – 2200mm
Surface: Black, Peeled, Rough machined or Grinded.
Delivery Condition: Annealed or QT
Core performance of P20 Mould Steel DIN 1.2311
P20 mould steel’s outstanding performance stems from its meticulously designed composition and rigorous manufacturing processes, delivering comprehensive performance advantages:
Pre-hardened delivery saves time and effort: This stands as one of P20’s most significant advantages. Prior to shipment, the steel mill subjects the material to special heat treatment, uniformly pre-hardening it to a hardness range of 28-34 HRC. This eliminates the need for cumbersome quenching processes upon receipt, allowing direct machining (milling, turning, drilling, engraving, etc.) and immediate deployment. Consequently, it substantially shortens the mould manufacturing cycle and accelerates time-to-market.
Superior Machinability and Polishability: Even in its pre-hardened state, P20 maintains excellent machinability, featuring low tool wear and high processing efficiency. Its uniformly fine microstructure enables mirror-like polishing (Ra ≤ 0.020μm), meeting the surface requirements for various high-finish plastic products (e.g., automotive lamp covers, appliance panels, cosmetic packaging).
Balanced strength, toughness and wear resistance: Through optimal alloying with chromium, nickel, molybdenum and other elements, P20 delivers sufficient hardness to resist wear while maintaining excellent toughness and impact resistance. This enables stable performance under high pressures, cyclic loads and minor impacts during plastic injection moulding, effectively preventing premature cracking and plastic deformation to ensure production safety and continuity.
Excellent Quenchability and Dimensional Stability: P20 exhibits uniform hardness distribution across cross-sections, ensuring consistent performance throughout large moulds. Its minimal heat treatment distortion and superior dimensional stability post-machining make it particularly suitable for manufacturing large, complex, and high-precision plastic moulds.
Moderate corrosion resistance: The chromium content provides fundamental protection, extending its service life compared to ordinary carbon steel when exposed to weakly corrosive plastic materials such as PVC.
Applications of P20 mould steel: Where is it required?
Leveraging these comprehensive properties, P20 mould steel excels across numerous sectors, particularly in:
Large, complex plastic moulds: For components such as automotive bumpers, dashboards, door panels, and grilles.
Moulds with high surface finish requirements: For television and computer monitor housings, air conditioning panels, washing machine drums, and various appliance casings requiring high gloss or fine texture.
General-purpose plastic moulds: For everyday plastic goods, toys, storage crates, containers, chairs, and similar items.
Moulds requiring extended service life: Moulds subjected to medium to high production volumes.
Extrusion mould bases and frames: Leveraging its excellent strength and toughness.
Our advantages in Processing P20 Mould Steel
We fully recognise that the quality of mould steel is pivotal to your production stability. Therefore, we implement the most stringent quality standards at every stage of P20 mould steel production:
Selecting Raw Materials: Rigorous quality control of incoming ferroalloys and scrap steel eliminates impurities at source.
Advanced Melting and Refining: Employing electric arc furnaces or advanced refining techniques (LF, VD, VOD) to precisely control chemical composition. Deep desulphurisation, dephosphorisation, and removal of non-metallic inclusions significantly enhance molten steel purity – crucial for ensuring polishability and toughness.
Precision Forging and Rolling Processes: Utilising heavy-tonnage forging or multi-directional rolling to fully refine grain structure, compact internal composition, eliminate casting defects, and enhance material density and isotropy.
Core Pre-hardening Heat Treatment Technology: The very essence of P20. Our computer-controlled continuous heat treatment line ensures uniform, stable target hardness (e.g., 30-32 HRC) across the entire cross-section, eliminating soft spots and hardness variations to establish a robust foundation for subsequent processing and application.
Comprehensive Non-Destructive Testing and Mechanical Properties Assessment: From ingot to finished product, we implement rigorous quality control through ultrasonic flaw detection, spectral analysis, hardness testing, and tensile impact tests. This ensures every delivered P20 plate/module is internally flawless, chemically compliant, and exhibits superior mechanical properties. 100% hardness inspection prior to dispatch is a fundamental requirement.
Not sure about the best equivalent for your application?
Why Manufacturers Choose Huangshi Xiri
Huangshi Xiri combines international-standard steel grades, a complete tool steel portfolio, strict quality control and reliable global supply. We match DIN / JIS / AISI equivalents precisely, offer cutting and heat-treatment services, and control every step from smelting to inspection. With stable capacity, on-time delivery and responsive technical support, we help manufacturers reduce risk, save costs and run production with confidence.
Contact Us
Contact Huangshi Xiri today for quotations, grade selection and technical support on tool steel, mold steel and alloy steel. Whether you need samples, cutting-to-size service or long-term supply for your projects, our engineers and sales team are ready to respond quickly with professional advice and reliable solutions for your manufacturing needs.
