1.2311 vs 1.2738
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.
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
1.2738
Mold Steel
1.2738 is P20 chemistry upgraded with about 1% nickel for through-hardening of very large molds. It keeps hardness uniform from surface to core in thick blocks and polishes better than plain 1.2311.
Standards: DIN 1.2738 · AISI P20+Ni / 718 type · GB 3Cr2NiMo
Chemical composition compared (%)
| Element | 1.2311 | 1.2738 |
|---|---|---|
| C | 0.28–0.40 | 0.35–0.45 |
| Si | 0.20–0.40 | 0.20–0.40 |
| Mn | 1.30–1.60 | 1.30–1.60 |
| P | ≤0.035 | — |
| S | ≤0.035 | — |
| Cr | 1.80–2.10 | 1.80–2.10 |
| Mo | 0.15–0.25 | 0.15–0.25 |
| Ni | — | 0.90–1.20 |
Properties compared
| Property | 1.2311 | 1.2738 |
|---|---|---|
| Delivery condition | Prehardened | Prehardened |
| Hardness | 280–325 HB | 290–330 HB |
| Tensile strength | 950–1100 MPa | 980–1150 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: 1.2311 · 1.2738. Substitution decisions for certified parts stay with the design authority.