Q235B vs S235JR
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.
Q235B
Structural & HSLA Steel
Q235B is China’s everyday carbon structural steel — the volume grade for domestic construction, plate, sections and welded tube. Grade B adds a room-temperature impact test over the basic A quality, making it the default export offer in this strength class.
Standards: DIN S235JR (near) · AISI A36 (near) · JIS SS400 (near) · GB Q235B (GB/T 700)
S235JR
Structural & HSLA Steel
S235JR is the baseline non-alloy structural steel of EN 10025-2, the default grade for ordinary steel construction across Europe. Its 235 MPa yield class and room-temperature impact guarantee cover the great majority of building and general fabrication work.
Standards: DIN 1.0038 (S235JR) · AISI A36 (near) · JIS SS400 (near) · GB Q235B (near)
Chemical composition compared (%)
| Element | Q235B | S235JR |
|---|---|---|
| C | 0.12–0.20 | ≤0.17 |
| Si | ≤0.30 | — |
| Mn | 0.30–0.70 | ≤1.40 |
| P | ≤0.045 | ≤0.035 |
| S | ≤0.045 | ≤0.035 |
| Cu | — | ≤0.55 |
Properties compared
| Property | Q235B | S235JR |
|---|---|---|
| Yield strength | ≥235 MPa (≤16 mm) | ≥235 MPa (≤16 mm; falls with thickness) |
| Tensile strength | 370–500 MPa | 360–510 MPa |
| Impact | B grade: 27 J at 20 °C | JR: 27 J at 20 °C |
| 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: Q235B · S235JR. Substitution decisions for certified parts stay with the design authority.