SteelWhat is P20 + Ni steel and what is it used for? Steel for large plastic molds
P20 + Ni steel is a steel for large plastic molds. In this guide we explain what P20 + Ni steel is, its chemical composition, its hardness, how it is heat treated, what it is used for, and what sizes we carry.
What is P20 + Ni steel?
A P20 variant with added nickel, supplied pre-hardened (quenched and tempered, ~30–34 HRC). Nickel improves hardenability, delivering uniform hardness even in large sections, with very good polishability for high-gloss finishes. For large plastic injection molds and high-polish cavities.
Chemical composition of P20 + Ni steel
This is the typical composition of P20 + Ni steel (standard AISI P20+Ni / EN-DIN 1.2738):
| Element | Contents | What for? |
|---|---|---|
| Carbon (C) | 0.35 – 0.45 % | Hardness and wear resistance |
| Silicon (Si) | 0.20 – 0.40 % | Deoxidizer |
| Manganese (Mn) | 1.30 – 1.60 % | Hardenability |
| Chromium (Cr) | 1.80 – 2.10 % | Hardenability and wear resistance |
| Nickel (Ni) | 0.90 – 1.20 % | Toughness and hardenability |
| Molybdenum (Mo) | 0.15 – 0.25 % | Hot hardness and hardenability |
| Phosphorus (P) | 0.030 % max. | Impurity, kept low |
| Sulfur (S) | 0.030 % max. | Impurity, kept low |
Hardness and heat treatment of P20 + Ni
The typical working hardness of P20 + Ni is 30 – 34 HRC (pre-hardened). It is supplied pre-hardened. Nickel improves hardenability, giving uniform hardness even in large sections, with very good polishability for high-gloss finishes. You can see the full overview in our article on heat treatments for steel, and hardness scales in steel hardness.
What is it used for? Applications of P20 + Ni
P20 + Ni steel is mainly used in:
- Injection molds
- Plastic molds
- Large molds
- Blow molds
- Mold cavities
- Mold plates
- Industrial mold bases
- Auto parts molds
- Mold inserts
Forms and sizes we carry
At NAT MAC we carry P20 + Ni steel in these forms and sizes:
| Package size | Sizes |
|---|---|
| Round bars | Ø 1/2" – 8" (Ø 13 – 203 mm) |
| Plates | 1/2" – 10" (13 – 254 mm) |
If you need a particular size, tell us which one and we will gladly source it for you.
P20 + Ni equivalents and standards
P20 + Ni steel is also identified by these standards: AISI P20+Ni / EN-DIN 1.2738. You can see how to read them in our article on steel standards.
In summary
- P20 + Ni is a steel for large plastic molds
- Typical composition: C 0.35 – 0.45 and Cr 1.80 – 2.10, plus alloying elements
- Typical working hardness: 30 – 34 HRC (pre-hardened)
- Ideal for large plastic molds and high-polish molds
- We carry it in round bar (1/2" – 8") and plates (1/2" – 10"), cut to size
Why buy your P20 + Ni steel from NAT MAC?
We have more than 54 years of experience as an industrial supplier and ISO 9001 certified quality. We carry a wide range of tool grade steels and help you choose the right one for your tool or mold.
- Quality P20 + Ni steel, with certification and traceability
- Material cut to the size you need
- Technical advice on choosing the right grade
- Wide range of tool-grade steels in stock
- On-time deliveries and competitive prices
Tell us what tool or mold you are going to make and in what dimensions, and we will recommend the right grade and form. Request your free quote.
Sources: data sheet from our NAT MAC catalog (composition, sizes and applications) and public industry references for working hardness. Values are for reference and may vary by standard, heat and treatment.
