SCM430 vs 4130
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.
SCM430
Alloy & Engineering Steel
SCM430 is the JIS G4053 chromium-molybdenum machine structural steel corresponding to AISI 4130, with a slightly higher manganese and chromium window in the JIS specification. It is one of the most traded alloy round bars in Japan and Southeast Asia for shafts, bolts and hydraulic components.
Standards: DIN 25CrMo4 / 1.7218 (near) · AISI 4130 · JIS SCM430 (JIS G4053) · GB 30CrMo (near)
4130
Alloy & Engineering Steel
4130 is a low-alloy Cr-Mo steel famous for weldable high strength in tube form — aircraft structures, racing chassis, bicycle frames and oilfield parts.
Standards: DIN 1.7218 (25CrMo4) · AISI 4130 · JIS SCM430 · GB 30CrMo
Chemical composition compared (%)
| Element | SCM430 | 4130 |
|---|---|---|
| C | 0.28–0.33 | 0.28–0.33 |
| Si | 0.15–0.35 | 0.15–0.35 |
| Mn | 0.60–0.85 | 0.40–0.60 |
| P | ≤0.030 | — |
| S | ≤0.030 | — |
| Cr | 0.90–1.20 | 0.80–1.10 |
| Mo | 0.15–0.30 | 0.15–0.25 |
Properties compared
| Property | SCM430 | 4130 |
|---|---|---|
| Tensile strength | ≥830 MPa (Q&T reference) | 560–670 MPa (annealed); 850–1000 MPa (normalized/Q&T) |
| Yield strength | ≥685 MPa (Q&T reference) | — |
| Density | 7.85 g/cm³ | 7.85 g/cm³ |
| Weldability | — | Good (thin sections) |
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: SCM430 · 4130. Substitution decisions for certified parts stay with the design authority.