5150 vs 5140
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.
5150
Alloy & Engineering Steel
5150 is a medium-high carbon chromium steel used for stronger springs, axles and gears. It is the chromium-step between plain 1050 and the full spring grade 5160.
Standards: DIN 50Cr4 type (near) · AISI 5150 · JIS SCr445 (near) · GB 50Cr
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
Chemical composition compared (%)
| Element | 5150 | 5140 |
|---|---|---|
| C | 0.48–0.53 | 0.38–0.43 |
| Si | 0.15–0.35 | 0.15–0.35 |
| Mn | 0.70–0.90 | 0.70–0.90 |
| P | ≤0.035 | — |
| S | ≤0.040 | — |
| Cr | 0.70–0.90 | 0.70–0.90 |
Properties compared
| Property | 5150 | 5140 |
|---|---|---|
| Hardness (Q&T) | 30–42 HRC typical | 28–38 HRC typical |
| Tensile strength | 900–1150 MPa (Q&T, typ.) | 850–1050 MPa (Q&T) |
| 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: 5150 · 5140. Substitution decisions for certified parts stay with the design authority.