1.2738 equivalent grades: ASTM, EN, JIS, GB, DIN

1.2738 is plastic mould steel, nickel-alloyed, pre-hardened specified in EN ISO 4957. Below, the grades that can replace it — 4 standard systems in all — with the deciding limit named for each one rather than left to be looked up. The full 1.2738 data sheet carries the composition and mechanical tables.

Last updated 12 October 2026

For 1.2738 the exact matches are 3Cr2MnNiMo, and material bought as one is accepted as the other without deviation. P20, 1.2311, 1.2311 and 1 more differ on one limit only — a carbon ceiling, an impact temperature or a strength minimum. At the functional level 4140, 1.2312, 1-2083 and 1 more serve as a replacement once the design has been re-run. The cross-reference below covers 1 in GB/T (China), 2 in AISI / SAE, 5 in EN (European), 1 in GOST (Russia/CIS).

Cross-reference table

Identical, near and functional are defined once on the grade index; the reason column below says which limit differs in each case.

1.2738 in GB/T (China)

• 3Cr2MnNiMo — Identical GB/T 1299 3Cr2MnNiMo (also written 3Cr2NiMnMo) is the direct transcription: C 0.32–0.40, Mn 1.10–1.50, Cr 1.70–2.00, Ni 0.85–1.15, Mo 0.25–0.40.

1.2738 in AISI / SAE

• P20 — Near AISI P20 modified with nickel is sold as P20+Ni and is the direct counterpart. Base P20 (C 0.28–0.40, Mn 0.60–1.00, Mo 0.30–0.55, no nickel) does not hold the band in large sections. North American certificates do not standardise the nickel level — ask for the analysis.
• 4140 — Functional The general-purpose quenched and tempered engineering steel at a similar hardness. Sold as bar and plate without mould-block sizes, cleanliness grading or guaranteed through-hardness, so it is used for frames and fixtures rather than cavities.

1.2738 in EN (European)

• 1.2311 — Near 40CrMnMo7: the same steel without nickel. Identical in use up to about 250 mm section and cheaper; above 400 mm its core hardness drops out of the band, which is exactly the gap 1.2738 fills.
• 1.2311 — 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.
• 1.2312 — Functional 40CrMnMoS8-6: free-machining mould base steel. Cuts faster and costs less, but the sulphide stringers make it unsuitable for polishing, texturing or welding and it has no nickel, so it is used for plates rather than cavities.
• 1-2083 — Functional X40Cr14: the stainless mould steel for corrosive polymers and cooling-channel corrosion, hardened to 48–52 HRC. Different purpose — it is bought for corrosion resistance, not for section size.
• 1.2344 — Functional X40CrMoV5-1 (H13) at 48–52 HRC: the choice when the mould runs hot or abrasively filled polymers erode the cavity. Far more expensive, must be heat treated after machining, and an unnecessary step for ordinary thermoplastics.

1.2738 in GOST (Russia/CIS)

• 40KhNM — Near GOST 4543 40KhNMA: C 0.37–0.44, Cr 0.60–0.90, Ni 1.25–1.75, Mo 0.15–0.25 — a nickel-chromium-molybdenum steel supplied quenched and tempered; less manganese and chromium than 1.2738.

Superseded names for 1.2738

• 40CrMnNiMo8-6-4 — DIN 17350 (withdrawn): Same number and name; the plastic mould steels moved into EN ISO 4957.
• GS-738 — older German trade usage: Still found on older mould drawings.
• M238 / Impax Supreme — Böhler / Uddeholm trade names: Thyroplast 2738, Cryodur 2738. Impax Supreme and M238 are remelted with controlled cleanliness; ordinary 1.2738 is not.
• 1.2738HH — supplier designation: Not a separate EN grade — the same analysis delivered at 38–42 HRC instead of 29–34 HRC.

Key data for 1.2738

Full composition, mechanical properties by thickness, heat treatment and applications for 1.2738 →

Verified against EN ISO 4957:2018. Last checked: October 2026.