P20+Ni is a chromium-nickel-molybdenum plastic mold steel, essentially an upgraded version of standard P20 (1.2311) with nickel added to the chemistry. It is used for plastic injection molds, blow molds, and die-casting dies, and is normally supplied pre-hardened so it can go straight into mold-making without further heat treatment.

P20+Ni contains 0.35–0.45% Carbon, 1.80–2.10% Chromium, 0.15–0.25% Molybdenum, 0.90–1.20% Nickel, 1.30–1.60% Manganese, 0.20–0.40% Silicon, with Phosphorus and Sulphur held to ≤0.030% each. The added nickel is what distinguishes this grade from standard P20 (1.2311).

Nickel improves hardenability and toughness, giving P20+Ni a much more uniform hardness through thick sections than standard P20 — an important advantage in large mold blocks where core-to-surface hardness variation would otherwise be a problem. Chromium and molybdenum continue to support wear resistance and a fine, homogeneous structure after heat treatment.

P20+Ni is typically supplied pre-hardened to 28–34 HRC (roughly 280–325 HB). Typical tensile strength is 1080–1180 MPa with a yield strength of 800 MPa and above, elongation of 15% or more, and an elastic modulus of around 205 GPa.

Supplying P20+Ni pre-hardened eliminates the distortion risk and lead time of an in-house hardening cycle. Mold makers can machine cavities, cores, and bases directly, with the nickel content keeping hardness far more uniform across large blocks than standard P20.

Yes. Where higher surface hardness or wear resistance is needed at the cavity face, P20+Ni can be nitrided, flame hardened, or induction hardened to raise surface hardness up to around 50 HRC, without affecting the core toughness of the block.

P20+Ni offers good machinability for a pre-hardened steel and takes a superior polish compared to sulphur-added grades such as 1.2312 (P20+S), which is why it is favoured for cosmetic-grade and deep-engraved injection mold cavities. Its consistent, fine-grained structure also makes it well suited to etching and texturing.

P20+Ni is used for large plastic injection mold cavities and cores, blow molds, mold bases and plates, bolsters, die holders, extrusion dies, and die-casting mold components. It is the preferred upgrade over standard P20 wherever a large mold block needs uniform hardness through thick sections without further hardening.

P20+Ni is suitable for zinc and aluminium die-casting dies and mold components, offering better hardenability than standard P20 in this role. For high-temperature or very demanding aluminium die-casting service, a dedicated hot-work grade such as H13 remains the correct choice.

P20+Ni has good weldability compared to high-carbon tool steels, which makes it practical to repair worn mold details or make engineering changes on the block. A matching filler wire is generally used for die and mold repair welding to preserve hardness and toughness at the repair.

P20+Ni is essentially P20 (1.2311) with nickel added, giving it improved hardenability and much more uniform hardness through large sections. Standard P20 remains a reliable, more economical choice for small to medium mold blocks, while P20+Ni is the upgrade for larger blocks or applications where consistent hardness throughout the section is critical.

Yes. P20+Ni (AISI/ASTM), DIN 1.2738 (also referred to as DIN 2738), and GB 3Cr2MnNiMo (China) are equivalent or closely comparable designations for the same nickel-modified P20 grade. Note that 1.2312 (P20+S) is a different, sulphur-added free-machining variant — always verify chemistry against your specification before substituting one for another.