4140 equivalent grades: ASTM, EN, JIS, GB, DIN
4140 is chromium-molybdenum low-alloy steel (chromoly) specified in ASTM A29. What follows is the substitution list: 6 standard systems, and for each candidate the clause that makes it an exact match or stops it being one. The full 4140 data sheet carries the composition and mechanical tables.
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4140 is cross-certified with 708M40 (EN19), 42CrMo4, 42CrMo and 1 more: the composition windows overlap closely enough that one certificate satisfies the other. 4142, 4130, 40KhM / 38KhM differ on one limit only — a carbon ceiling, an impact temperature or a strength minimum. 4340, 1045 serve the same purpose without being the same steel, so a substitution there needs the design re-checked rather than the certificate. Across systems that is 1 in BS (superseded British), 1 in EN (European), 1 in GB/T (China), 1 in JIS (Japan), 4 in AISI / SAE, 1 in GOST (Russia/CIS).
Cross-reference table
| Grade | System | Match | Why / differences |
|---|---|---|---|
| 708M40 (EN19) | BS (superseded British) | Identical | BS 970 708M40: C 0.36–0.44, Cr 0.90–1.20, Mo 0.15–0.25. |
| 42CrMo4 | EN (European) | Identical | 1.7225: C 0.38–0.45, Cr 0.90–1.20, Mo 0.15–0.30 — windows overlap almost completely; dual-certified 4140/42CrMo4 bar is standard. |
| 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. |
| 4142 | AISI / SAE | Near | C 0.40–0.45 — the upper half of the 42CrMo4 range; slightly higher hardness. |
| 4130 | AISI / SAE | Near | 0.30 % C version: lower strength (≈ 1000 MPa max practical), far better weldability; used for tube and welded structures. |
| 40KhM / 38KhM | GOST (Russia/CIS) | Near | GOST 4543 38KhM (C 0.35–0.42) / 40KhMFA (V-bearing); 40KhM is the common Russian equivalent in practice. |
| 4340 | AISI / SAE | Functional | Adds 1.8 % Ni: deeper hardenability (sections > 100 mm), higher toughness at 1500+ MPa. |
| 1045 | AISI / SAE | Functional | Unalloyed medium-carbon: cheaper, through-hardens only ≤ 20 mm. |
Identical, near and functional are defined once on the grade index; the reason column below says which limit differs in each case.
4140 in BS (superseded British)
- 708M40 (EN19) — Identical BS 970 708M40: C 0.36–0.44, Cr 0.90–1.20, Mo 0.15–0.25.
4140 in EN (European)
- 42CrMo4 — Identical 1.7225: C 0.38–0.45, Cr 0.90–1.20, Mo 0.15–0.30 — windows overlap almost completely; dual-certified 4140/42CrMo4 bar is standard.
4140 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.
4140 in JIS (Japan)
- SCM440 — Identical JIS G4053 SCM440: C 0.38–0.43, Cr 0.90–1.20, Mo 0.15–0.30.
4140 in AISI / SAE
- 4142 — Near C 0.40–0.45 — the upper half of the 42CrMo4 range; slightly higher hardness.
- 4130 — Near 0.30 % C version: lower strength (≈ 1000 MPa max practical), far better weldability; used for tube and welded structures.
- 4340 — Functional Adds 1.8 % Ni: deeper hardenability (sections > 100 mm), higher toughness at 1500+ MPa.
- 1045 — Functional Unalloyed medium-carbon: cheaper, through-hardens only ≤ 20 mm.
4140 in GOST (Russia/CIS)
- 40KhM / 38KhM — Near GOST 4543 38KhM (C 0.35–0.42) / 40KhMFA (V-bearing); 40KhM is the common Russian equivalent in practice.
Superseded names for 4140
- G41400 — UNS: 4140H = H41400 (hardenability band).
- 42CrMo4 / 1.7225 — EN 10083-3: European twin; 42CrMoS4 (1.7227) free-machining.
- 708M40 / 708A42 / EN19 — BS 970 (withdrawn): EN19 is the old British name still used in the UK and India.
- SCM440 — JIS G4053: Japanese twin (SCM4 in older editions).
- 4145H / 4145H Mod — API Spec 7-1: Higher-carbon variant for drill collars and tool joints.
Key data for 4140
Full composition, mechanical properties by thickness, heat treatment and applications for 4140 →
Verified against ASTM A29/A29M-20 (SAE J404 chemistry). Last checked: September 2026.