S235JR and S275JR are structural steels, with the primary difference being yield strength: S275JR offers a higher minimum yield strength (275 MPa) compared to S235JR (235 MPa), making it stronger for more demanding applications like heavy machinery or large structures, while S235JR is used for general construction, though S275JR generally has slightly lower elongation and higher tensile strength, with both offering good weldability and machinability.
S235JR and S275JR are two of the most commonly specified European structural carbon steels used in plate, sheet, and rolled sections.
The principal technical difference between these grades is the specified minimum yield strength (the numeric grade identifier), which drives different design choices: S275JR delivers higher minimum yield strength than S235JR while maintaining similar chemistry and basic processing routes.
Chemical Composition
| Element | S235JR (typical, wt%) | S275JR (typical, wt%) |
|---|---|---|
| C (Carbon) | ≤ ~0.17–0.20 (low) | ≤ ~0.20–0.22 (low–moderate) |
| Mn (Manganese) | ~0.8–1.6 (moderate) | ~1.0–1.6 (moderate) |
| Si (Silicon) | ≤ ~0.3 (deoxidizer) | ≤ ~0.3 (deoxidizer) |
| P (Phosphorus) | ≤ 0.035 (impurity control) | ≤ 0.035 (impurity control) |
| S (Sulfur) | ≤ 0.035 (impurity control) | ≤ 0.035 (impurity control) |
| Cr (Chromium) | typically ≤ trace | typically ≤ trace |
| Ni (Nickel) | typically ≤ trace | typically ≤ trace |
| Mo (Molybdenum) | typically ≤ trace | typically ≤ trace |
| V, Nb, Ti, B (microalloys) | generally not present in significant amounts | generally not present in significant amounts |
| N (Nitrogen) | low (residual) | low (residual) |
Mechanical Properties
| Property | S235JR (typical) | S275JR (typical) |
|---|---|---|
| Minimum Yield Strength (Rp0.2) | 235 MPa | 275 MPa |
| Tensile Strength (Rm) | 360–510 MPa | 410–560 MPa |
| Elongation (A) | ≥ ~22–26% (depends on section/thickness) | ≥ ~20–23% (depends on section/thickness) |
| Charpy Impact (JR) | 27 J at 20°C (JR grade requirement) | 27 J at 20°C (JR grade requirement) |
| Hardness | Typical ranges ~110–150 HB (varies with condition) | Typical ranges ~120–160 HB (varies with condition) |
| Parameter | S235JR | S275JR |
|---|---|---|
| Weldability | Excellent | Excellent (slightly higher CE potential) |
| Strength–Toughness balance | Good (higher ductility) | Better strength with retained toughness |
| Cost | Lower (generally) | Moderate (generally higher than S235JR) |
