1.2311 equivalent grades: ASTM, EN, JIS, GB, DIN
1.2311 is plastic mould steel, pre-hardened and tempered specified in EN ISO 4957. Below, the grades that can replace it — 5 standard systems in all — with the deciding limit named for each one rather than left to be looked up. The full 1.2311 data sheet carries the composition and mechanical tables.
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P20, 1.2312, 1.2738 and 2 more differ by one requirement, which is a line on the order rather than a redesign. 42CrMo4, 1-2083, SCM440 / 42CrMo serve in the same applications, but the composition differs enough that the engineer signs it off, not the buyer. Counted by system: 1 in AISI / SAE, 4 in EN (European), 1 in GB/T (China), 1 in GOST (Russia/CIS), 1 in JIS (Japan).
Cross-reference table
| Grade | System | Match | Why / differences |
|---|---|---|---|
| P20 | AISI / SAE | Near | AISI P20 (ASTM A681): C 0.28–0.40, Mn 0.60–1.00, Cr 1.40–2.00, Mo 0.30–0.55. The same pre-hardened mould steel concept, but leaner on manganese and richer on molybdenum, so a thick P20 block has a lower core hardness than a 1.2311 block of the same size. Interchangeable for mould bases; check the hardness certificate, not the name. |
| 1.2312 | EN (European) | Near | 40CrMnMoS8-6: the same steel with 0.05–0.10 % sulphur added. Machines about 20 % faster and is the standard choice for mould bases, but the sulphide stringers make it unsuitable for polishing, texturing or welding. |
| 1.2738 | EN (European) | Near | 40CrMnNiMo8-6-4: 1.2311 with 1 % nickel added. Holds 28–34 HRC in blocks up to 600 mm and above, where 1.2311 drops below 28 HRC in the core. The default for large moulds. |
| 3Cr2Mo | GB/T (China) | Near | GB/T 1299 3Cr2Mo is the Chinese P20 transcription: C 0.28–0.40, Cr 1.40–2.00, Mo 0.30–0.55. 3Cr2MnNiMo corresponds to 1.2738. |
| 40KhGM | GOST (Russia/CIS) | Near | GOST 4543 40KhGM: C 0.37–0.45, Mn 0.90–1.20, Cr 0.90–1.20, Mo 0.20–0.30 — the closest Russian analysis, with less chromium. |
| 42CrMo4 | EN (European) | Functional | 1.7225: the general-purpose quenched and tempered engineering steel. Similar hardness at delivery and cheaper, but supplied in bar rather than mould-block sizes and without the cleanliness and flatness guarantees a mould base needs. |
| 1-2083 | EN (European) | Functional | X40Cr14: the stainless mould steel. Chosen when the moulded polymer is corrosive (PVC, fluoropolymers, flame-retardant compounds) or the mould must survive condensation; harder to machine and a step up in price. |
| SCM440 / 42CrMo | JIS (Japan) | Functional | JIS has no dedicated pre-hardened mould grade; Japanese mould bases are commonly SCM440 (42CrMo4 class) supplied quenched and tempered to 28–33 HRC, which performs the same job with lower manganese and 0.20 % more molybdenum. |
Identical, near and functional are defined once on the grade index; the reason column below says which limit differs in each case.
1.2311 in AISI / SAE
- P20 — Near AISI P20 (ASTM A681): C 0.28–0.40, Mn 0.60–1.00, Cr 1.40–2.00, Mo 0.30–0.55. The same pre-hardened mould steel concept, but leaner on manganese and richer on molybdenum, so a thick P20 block has a lower core hardness than a 1.2311 block of the same size. Interchangeable for mould bases; check the hardness certificate, not the name.
1.2311 in EN (European)
- 1.2312 — Near 40CrMnMoS8-6: the same steel with 0.05–0.10 % sulphur added. Machines about 20 % faster and is the standard choice for mould bases, but the sulphide stringers make it unsuitable for polishing, texturing or welding.
- 1.2738 — Near 40CrMnNiMo8-6-4: 1.2311 with 1 % nickel added. Holds 28–34 HRC in blocks up to 600 mm and above, where 1.2311 drops below 28 HRC in the core. The default for large moulds.
- 42CrMo4 — Functional 1.7225: the general-purpose quenched and tempered engineering steel. Similar hardness at delivery and cheaper, but supplied in bar rather than mould-block sizes and without the cleanliness and flatness guarantees a mould base needs.
- 1-2083 — Functional X40Cr14: the stainless mould steel. Chosen when the moulded polymer is corrosive (PVC, fluoropolymers, flame-retardant compounds) or the mould must survive condensation; harder to machine and a step up in price.
1.2311 in GB/T (China)
- 3Cr2Mo — Near GB/T 1299 3Cr2Mo is the Chinese P20 transcription: C 0.28–0.40, Cr 1.40–2.00, Mo 0.30–0.55. 3Cr2MnNiMo corresponds to 1.2738.
1.2311 in GOST (Russia/CIS)
- 40KhGM — Near GOST 4543 40KhGM: C 0.37–0.45, Mn 0.90–1.20, Cr 0.90–1.20, Mo 0.20–0.30 — the closest Russian analysis, with less chromium.
1.2311 in JIS (Japan)
- SCM440 / 42CrMo — Functional JIS has no dedicated pre-hardened mould grade; Japanese mould bases are commonly SCM440 (42CrMo4 class) supplied quenched and tempered to 28–33 HRC, which performs the same job with lower manganese and 0.20 % more molybdenum.
Superseded names for 1.2311
- 40CrMnMo7 — DIN 17350 (withdrawn): Same number and name; the plastic mould steels moved into EN ISO 4957.
- GS-711 — older German trade usage: Still seen on drawings as a synonym for 1.2311.
- 40CrMnMo8 — older designation: Occasionally used for the same steel; the modern short name is 40CrMnMo7.
- M200 / Impax — Böhler / Uddeholm trade names: Thyroplast 2311, Cryodur 2311. Impax Supreme is the remelted, higher-cleanliness version.
Key data for 1.2311
Yield≈ 800–900 MPa +QT as delivered, section ≤ 250 mm
Tensile1000–1100 MPa
Carbon0.35 – 0.45 %
StandardEN ISO 4957
Full composition, mechanical properties by thickness, heat treatment and applications for 1.2311 →
Verified against EN ISO 4957:2018. Last checked: October 2026.