5140 vs 40Cr
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.
5140
Alloy & Engineering Steel
5140 is a medium-carbon chromium steel for moderately loaded shafts, gears and bolts — the chromium-only (no molybdenum) economy alternative to 4140.
Standards: DIN 1.7035 (41Cr4) · AISI 5140 · JIS SCr440 · GB 40Cr
40Cr
Alloy & Engineering Steel
40Cr is China’s most-used alloy structural steel (GB/T 3077) — a Cr steel equivalent to AISI 5140 and JIS SCr440, stocked everywhere in China as round bar.
Standards: DIN 1.7035 (41Cr4) · AISI 5140 · JIS SCr440 · GB 40Cr
Chemical composition compared (%)
| Element | 5140 | 40Cr |
|---|---|---|
| C | 0.38–0.43 | 0.37–0.44 |
| Si | 0.15–0.35 | 0.17–0.37 |
| Mn | 0.70–0.90 | 0.50–0.80 |
| Cr | 0.70–0.90 | 0.80–1.10 |
Properties compared
| Property | 5140 | 40Cr |
|---|---|---|
| Hardness (Q&T) | 28–38 HRC typical | 28–38 HRC typical |
| Tensile strength | 850–1050 MPa (Q&T) | ≥980 MPa (Q&T reference, GB/T 3077) |
| Density | 7.85 g/cm³ | 7.85 g/cm³ |
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: 5140 · 40Cr. Substitution decisions for certified parts stay with the design authority.