S235JR vs S355J2: differences explained
S235 vs S355: yield 235 vs 355 MPa, tensile 360–510 vs 470–630 MPa, price +5–10 %, weldability CEV 0.35 vs 0.45. Which EN 10025 structural steel to choose, with the full side-by-side table.
Overview
S235 and S355 are the two ends of the everyday EN 10025-2 structural range — the same low-carbon steel family, the same delivery forms, the same mills, but a 50 % difference in yield strength that changes section sizes, weld procedures and price. S235JR is the base grade; S355J2 is the plate grade specified for cranes, bridges and machinery. This page puts the numbers side by side and says when each one is the right choice.
The short version: S355 costs only 5–10 % more per tonne but carries 50 % more load per kilogram, so any strength-governed member should be S355. S235 wins when deflection, buckling of slender elements, easy forming, or minimal welding control matter more than strength.
S235JR vs S355J2 side by side
| Property | S235JR | S355J2 |
|---|---|---|
| Standard | EN 10025-2:2019 | EN 10025-2:2019 |
| Material number | 1.0038 | 1.0577 |
| Old names | St37-2, Fe360B, 40B | St52-3 N, Fe510D, 50D |
| Min. yield ReH, ≤ 16 mm | 235 MPa (34 ksi) | 355 MPa (51 ksi) |
| Min. yield, 40–63 mm | 215 MPa | 335 MPa |
| Tensile Rm, 3–100 mm | 360–510 MPa | 470–630 MPa |
| Elongation A, ≤ 40 mm | ≥ 26 % | ≥ 22 % |
| Impact (Charpy V) | 27 J at +20 °C | 27 J at −20 °C |
| Carbon max | 0.17 % (≤ 40 mm) | 0.22 % |
| Mn max | 1.40 % | 1.60 % |
| P / S max | 0.035 / 0.035 % | 0.025 / 0.025 % |
| CEV max, ≤ 30 mm | 0.35 % | 0.45 % |
| Deoxidation | optional (FN) | fully killed (FF) |
| Preheat for welding | none to ~40 mm | consider above 25 mm (EN 1011-2) |
| Typical hardness | 100–140 HB | 150–190 HB |
| Min. bend radius, 8–16 mm (transverse) | 2.0 t | 3.0 t |
| Design fy (EN 1993-1-1), t ≤ 40 mm | 235 MPa | 355 MPa |
| Relative price per tonne (2026, coil/plate) | 1.00 | ≈ 1.05–1.10 |
| Strength per € (yield/price) | 1.00 | ≈ 1.40 |
| Typical use | secondary steelwork, frames, general fabrication | primary structure, cranes, bridges, machinery, heavy transport |
Which should you choose?
Choose S355J2 when strength governs: beams, columns, crane girders, lifting gear, trailers, anything designed to EN 1993 where a smaller section saves weight or the load is high. The 5–10 % price premium is repaid by 30–35 % lighter members. You also get −20 °C toughness and cleaner steel.
Choose S235JR when strength does not govern: deflection-limited beams (stiffness E is identical, so S355 does not help), slender elements that fail by buckling before yield, parts that will be cold-formed with tight radii, thin sheet, galvanized handrails and fences, and small shops without welding-procedure control. It is also the grade to order when a drawing says St37 or A36.
Do not mix them unmarked on one job: S355 in the wrong place is harmless, but S235 substituted where S355 was designed is a 34 % strength shortfall.
- Deflection- or vibration-limited design (stiffness governs)
- Slender compression members where buckling limits capacity
- Cold forming with tight bend radii, roll-formed profiles
- Galvanized architectural and light steelwork
- Shops without preheat and welding-procedure control
- Drawings calling St37-2, A36, SS400 or Q235
- Strength-governed beams, columns, plate girders
- Cranes, lifting equipment, hoists (EN 13001)
- Bridges, wind towers, offshore secondary steel
- Truck and trailer chassis, heavy transport
- Machinery frames with high stress
- Any service below 0 °C (J2 toughness)
Frequently asked questions
What is the difference between S235 and S355?
Yield strength: 235 vs 355 MPa (up to 16 mm) — S355 is 51 % stronger. Tensile 360–510 vs 470–630 MPa. S355 allows more carbon and manganese (CEV 0.45 vs 0.35 %), so thick S355 needs welding care; S355J2 is also tested at −20 °C and is cleaner (P/S ≤ 0.025 %).
Is S355 much more expensive than S235?
No — typically 5–10 % more per tonne for plate and coil, sometimes less for sections. Per unit of load capacity S355 is about 40 % cheaper, which is why primary structures use it.
Is S355 harder to weld than S235?
Slightly. Both weld with standard E42/E46 consumables without preheat in thin sections; S355 above ~25 mm or in restrained joints should have preheat calculated per EN 1011-2 because its carbon equivalent can reach 0.45 %. Low-hydrogen consumables are standard for S355.
Can I replace S235 with S355?
Yes, upward substitution is always safe for strength. Check only that welding procedures suit the higher CEV, and that the extra strength does not change the failure mode in fatigue-critical or ductility-governed details.
Which is stiffer, S235 or S355?
Neither — Young's modulus is 210 GPa for both. A beam of the same section deflects identically; S355 only lets you use a smaller section if strength, not deflection, is the limit.
What are S235JR and S355J2 called in ASTM and DIN?
S235JR ≈ ASTM A36 (250 MPa) and DIN St37-2; S355J2 ≈ ASTM A572 Grade 50 (345 MPa, add Charpy) and DIN St52-3 N.
Related comparisons
Verified against EN 10025-2:2019. Last checked: September 2026.