P20 vs 1.2311
These two grades are listed as equivalents of each other: their chemistry windows overlap and they serve the same applications. They are not always identical — check the differences below before substituting, especially in certified designs.
P20
Mold Steel
P20 is the American prehardened mold steel standard (ASTM A681), a Cr-Mo steel used for plastic injection molds worldwide. It balances machinability, polishability and toughness at moderate cost.
Standards: DIN 1.2311 (close) · AISI P20 · GB 3Cr2Mo
1.2311
Mold Steel
1.2311 is a prehardened Cr-Mn-Mo plastic mold steel, the European workhorse for injection molds and die holders. It is delivered ready to machine at 280–325 HB, with uniform hardness through large sections.
Standards: DIN 1.2311 · AISI P20 (close) · GB 3Cr2Mo
Chemical composition compared (%)
| Element | P20 | 1.2311 |
|---|---|---|
| C | 0.28–0.40 | 0.28–0.40 |
| Si | 0.20–0.40 | 0.20–0.40 |
| Mn | 0.60–1.00 | 1.30–1.60 |
| Cr | 1.40–2.00 | 1.80–2.10 |
| Mo | 0.30–0.55 | 0.15–0.25 |
| P | — | ≤0.035 |
| S | — | ≤0.035 |
Properties compared
| Property | P20 | 1.2311 |
|---|---|---|
| Delivery condition | Prehardened | Prehardened |
| Hardness | 280–325 HB | 280–325 HB |
| Tensile strength | 950–1100 MPa | 950–1100 MPa |
| Density | 7.85 g/cm³ | 7.85 g/cm³ |
| Thermal conductivity | — | 34 W/m·K |
Sourcing either grade?
Nasteel stocks both families from Shenzhen with EN 10204 3.1 mill certificates by heat number.
Ask for a quotationSee full data sheets: P20 · 1.2311. Substitution decisions for certified parts stay with the design authority.