1.0570 - S355 - 11 523
| Delivery condition | Description | Application |
|---|---|---|
| +AR, as rolled | Hot rolled, without further heat treatment | Standard structures, welded profiles |
| +N, normalized | Normalized, refined structure, improved toughness | Stressed welded structures, machines, beams |
| +M, thermomechanically rolled | High strength, fine-grained structure | Bridge structures, cranes, pressure vessels |
| +C | Cold drawn / calibrated | Precision bars, shafts, components requiring dimensional accuracy |
| +QT | Quenched and tempered, less common for S355 | Applications requiring higher strength and toughness |
⚙️ Basic steel designation
| Designation system | Designation | Note |
|---|---|---|
| Numerical designation, EN | 1.0570 | according to EN 10027-2 |
| EN / ISO designation | S355J2 or S355J2G3 | modern European designation |
| ČSN designation, Slovak standard | 11 523 | traditional designation according to ČSN 41 1523 |
| DIN designation, older | St 52-3 | German designation used until 1990 |
| Steel type | Non-alloy structural steel with higher strength | hot rolled |
🔩 Properties
Good weldability without the need for preheating, at standard thicknesses.
High toughness even at low temperatures, -20 °C.
Suitable for hot and cold forming.
Good machinability, bendability and cuttability.
Tensile strength, Rm: approx. 470–630 MPa
Yield strength, Re: approx. 355 MPa
Elongation, A5: 20–25 %
Hardness: approx. 150–200 HB
🧰 Applications
Building structures, beams, frames and bridges
Mechanical engineering structures
General metal products requiring strength and toughness
⚗️ Chemical composition
| Element | Content (%) |
|---|---|
| C | ≤ 0.20 |
| Si | 0.15–0.50 |
| Mn | max. 1.20 |
| P | ≤ 0.035 |
| S | ≤ 0.035 |
| Cu | ≤ 0.55 |
| Ni, Cr, Mo | small amounts, according to specification |
🔥 Typical heat treatment
| Process | Temperature (°C) | Medium / Procedure | Purpose and result |
|---|---|---|---|
| Soft annealing | 680–720 | Slow cooling in furnace | Removal of internal stresses after forming or welding, improved machinability |
| Normalizing | 880–940 | Air cooling | Grain refinement, improved toughness and strength, structure homogenization |
| Hardening | — | Not commonly used | Steel is not intended for hardening, due to low carbon content |
| Tempering | 550–680 | Air | Performed after normalizing, improved toughness |
| Stress relief annealing | 530–580 | Air cooling | Removal of internal stresses after machining or welding |
| Hot forming | 850–1100 | Subsequent slow cooling | Forged or rolled parts |
| Cold forming | — | Cold deformation possible | Material hardening may occur; subsequent annealing is recommended |
⚙️ Important notes
Steel 1.0570 is not intended for hardening – it is not a tool steel, but a structural steel.
The most commonly used process is normalizing (+N), which improves toughness and strength.
In practice, condition +AR, as rolled, is also often used without heat treatment.
🧰 Typical use after heat treatment
+N, normalized – for welded and stressed structures, frame beams, columns and machine parts.
+AR, as rolled – for standard profiles, tubes and plates.
+M, thermomechanically rolled – for cranes, bridges and pressure vessels.
