42CrMo4 equivalent grades: ASTM, EN, JIS, GB, DIN
Cross-reference for 42CrMo4 across standard systems. Each match is graded so you can see how safe the substitution is. Chromium-molybdenum steel for quenching and tempering — full 42CrMo4 data sheet.
Cross-reference table
| Grade | System | Match | Why / differences |
|---|---|---|---|
| 4140 | AISI / SAE | Identical | AISI 4140 (UNS G41400): C 0.38–0.43, Cr 0.80–1.10, Mo 0.15–0.25, Mn 0.75–1.00. Windows overlap almost completely; mills dual-certify 42CrMo4/4140. |
| 708M40 | BS (superseded British) | Identical | BS 970 708M40: C 0.36–0.44, Cr 0.90–1.20, Mo 0.15–0.25. |
| 42CrMo | GB/T (China) | Identical | GB/T 3077 42CrMo: C 0.38–0.45, Cr 0.90–1.20, Mo 0.15–0.25. |
| SCM440 | JIS (Japan) | Identical | JIS G4053 SCM440: C 0.38–0.43, Cr 0.90–1.20, Mo 0.15–0.30 — matches 42CrMo4 exactly on Cr and Mo. |
| 4142 | AISI / SAE | Near | C 0.40–0.45 — covers the upper half of the 42CrMo4 carbon range. |
| 42CrMoS4 | EN (European) | Near | Same grade with controlled S (0.020–0.040 %) for free machining; slightly lower transverse toughness. |
| 40KhM / 38KhM | GOST (Russia/CIS) | Near | GOST 4543 38KhM (C 0.35–0.42, Cr 0.90–1.30, Mo 0.20–0.30); 40KhM is the nearer Russian practice grade. |
| 34CrNiMo6 | EN (European) | Functional | Ni-bearing alternative with deeper hardenability for sections above ~100 mm. |
| C45 | EN (European) | Functional | Unalloyed, cheaper, but through-hardens only in thin sections. |
Identical = same composition and mechanical limits within rounding. Near = one limit differs (e.g. carbon max or impact temperature). Functional = interchangeable for most uses after an engineering check.
How the matches are graded
Identical means the chemical composition windows overlap so that material certified to one specification meets the other without deviation, and the mechanical minimums are the same or the other is inside them — mills usually dual-certify. Near means one limit differs (a carbon maximum, an impact temperature, a strength minimum or a delivery condition) and a substitution needs a one-line engineering check. Functional means the grades serve the same purpose but are not the same steel — a designer can often use one for the other, but only after re-checking the design.
42CrMo4 in AISI / SAE
- 4140 — Identical AISI 4140 (UNS G41400): C 0.38–0.43, Cr 0.80–1.10, Mo 0.15–0.25, Mn 0.75–1.00. Windows overlap almost completely; mills dual-certify 42CrMo4/4140.
- 4142 — Near C 0.40–0.45 — covers the upper half of the 42CrMo4 carbon range.
42CrMo4 in BS (superseded British)
- 708M40 — Identical BS 970 708M40: C 0.36–0.44, Cr 0.90–1.20, Mo 0.15–0.25.
42CrMo4 in GB/T (China)
- 42CrMo — Identical GB/T 3077 42CrMo: C 0.38–0.45, Cr 0.90–1.20, Mo 0.15–0.25.
42CrMo4 in JIS (Japan)
- SCM440 — Identical JIS G4053 SCM440: C 0.38–0.43, Cr 0.90–1.20, Mo 0.15–0.30 — matches 42CrMo4 exactly on Cr and Mo.
42CrMo4 in EN (European)
- 42CrMoS4 — Near Same grade with controlled S (0.020–0.040 %) for free machining; slightly lower transverse toughness.
- 34CrNiMo6 — Functional Ni-bearing alternative with deeper hardenability for sections above ~100 mm.
- C45 — Functional Unalloyed, cheaper, but through-hardens only in thin sections.
42CrMo4 in GOST (Russia/CIS)
- 40KhM / 38KhM — Near GOST 4543 38KhM (C 0.35–0.42, Cr 0.90–1.30, Mo 0.20–0.30); 40KhM is the nearer Russian practice grade.
Superseded names for 42CrMo4
- 42CrMo4 (1.7225) — DIN 17200 (withdrawn): Name and number unchanged since DIN 17200; only the standard moved to EN 10083-3.
- 708M40 / 708A42 — BS 970
- 42CD4 — NF A 35-552
- 42CrMo4 — UNI 7845
Key data for 42CrMo4
Full composition, mechanical properties by thickness, heat treatment and applications for 42CrMo4 →
Verified against EN 10083-3:2006. Last checked: September 2026.