P20 Tool Steel – Frequently Asked Questions
P20 is a versatile, pre-hardened mold steel (28–34 HRC) widely used for plastic injection molds, die casting dies, and blow molds. It offers good machinability, polishability, and toughness without requiring additional heat treatment.
P20 typically contains: Carbon (0.28–0.40%), Chromium (1.40–2.00%), Molybdenum (0.30–0.55%), Manganese (0.60–1.00%), and Silicon (0.20–0.80%), which together provide strength, toughness, and good wear resistance.
P20 is supplied pre-hardened to 28–34 HRC. It can be further case-hardened or nitrided to achieve surface hardness up to 60+ HRC while retaining a tough core.
P20 is commonly used for plastic injection mold bases and cavities, blow molds, die casting dies, structural components, jigs and fixtures, and automotive interior trim molds.
P20 is heavily used in the plastics industry, automotive sector, consumer electronics, packaging, medical device manufacturing, and aerospace for tooling and structural components.
P20+Ni contains added nickel (0.80–1.20%), which improves toughness, through-hardening for thicker sections, and polishability — making it preferred for large molds and mirror-finish applications.
P20 is a cold/warm work mold steel best for plastic molding at moderate temperatures, while H13 is a hot work tool steel designed for high-temperature applications like aluminum die casting and forging dies. H13 offers superior heat resistance; P20 offers better machinability.
Yes, P20 can be welded using matching filler materials with proper pre-heat (200–300°C) and post-weld tempering to avoid cracking and restore hardness uniformity.
Yes, P20 responds well to gas or plasma nitriding, achieving a surface hardness of 55–65 HRC, which significantly improves wear resistance and extends mold life.
Yes — P20 has excellent machinability in its pre-hardened state (28–34 HRC), making it easier and more cost-effective to machine compared to fully hardened steels, reducing lead time for mold production.
Standard P20 can achieve a fine polish (up to VDI 12), while P20+Ni (modified) can achieve mirror-like finishes (VDI 3–6 / SPI-A2), making it suitable for transparent or high-gloss plastic parts.
ESR (Electro Slag Remelted) P20 offers superior cleanliness, fewer inclusions, improved toughness, and better polishability compared to conventional P20. It is preferred for high-quality, large-section molds.
P20 offers a strong balance of pre-hardened supply condition (no heat treatment needed), good toughness and wear resistance, excellent machinability, cost-effectiveness, wide availability in large block sizes, and easy weldability.
