34CrMo4 vs 4135
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.
34CrMo4
Alloy & Engineering Steel
34CrMo4 is the EN Q&T Cr-Mo steel (1.7220) one step below 42CrMo4, the European counterpart of the 4135/SCM435 family. It is widely used for gas cylinders, shafts and high-strength fasteners.
Standards: DIN 1.7220 (34CrMo4) · AISI 4135 (near) · JIS SCM435 (near) · GB 35CrMo (near)
4135
Alloy & Engineering Steel
4135 is the mid-carbon Cr-Mo Q&T steel one step below 4140, matching JIS SCM435 and GB 35CrMo almost exactly. It is a staple of Asian and European bar trade for shafts and high-strength bolts.
Standards: DIN 1.7220 (34CrMo4, near) · AISI 4135 · JIS SCM435 · GB 35CrMo
Chemical composition compared (%)
| Element | 34CrMo4 | 4135 |
|---|---|---|
| C | 0.30–0.37 | 0.33–0.38 |
| Si | ≤0.40 | 0.15–0.35 |
| Mn | 0.60–0.90 | 0.70–0.90 |
| P | ≤0.025 | ≤0.035 |
| S | ≤0.035 | ≤0.040 |
| Cr | 0.90–1.20 | 0.80–1.10 |
| Mo | 0.15–0.30 | 0.15–0.25 |
Properties compared
| Property | 34CrMo4 | 4135 |
|---|---|---|
| Hardness (Q&T) | 28–40 HRC typical | 28–38 HRC typical |
| Tensile strength | 800–1100 MPa (Q&T, EN 10083 section bands) | 850–1050 MPa (Q&T, typ.) |
| 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: 34CrMo4 · 4135. Substitution decisions for certified parts stay with the design authority.