Steel Grade Datasheet
S355J2/ 1.0577 / ≈ A572 Gr.50
High-Strength Low-Alloy Structural Steel (HSLA)
What is S355J2 (St52) steel?
S355J2 (Werkstoff No. 1.0577, formerly St52-3) is a high-strength low-alloy structural steel per EN 10025-2. The '355' denotes a minimum yield strength of 355 MPa for sections ≤16 mm; 'J2' denotes a minimum impact toughness of 27 J at −20 °C. Tensile strength is 470–630 MPa. With roughly 50% higher yield than S235, it is the standard grade for heavy steel construction, bridges and cranes, and its low carbon equivalent (CEV ≤0.45) makes it readily weldable.
Chemical Composition
Cast analysis, % by weight (per the applicable EN standard)
| Element | Range (%) |
|---|---|
| C | ≤ 0.20 |
| Si | ≤ 0.55 |
| Mn | ≤ 1.60 |
| P | ≤ 0.025 |
| S | ≤ 0.025 |
| Cu | ≤ 0.55 |
| CEV | ≤ 0.45 |
Mechanical Properties (+N)
Values depend on ruling section / thickness (d).
| Section (mm) | Yield Re min (MPa) | Tensile Rm (MPa) | Elongation A min (%) |
|---|---|---|---|
| d ≤ 16 | 355 | 470–630 | 22 |
| 16 < d ≤ 40 | 345 | 470–630 | 22 |
| 40 < d ≤ 63 | 335 | 470–630 | 21 |
| 63 < d ≤ 100 | 325 | 470–630 | 20 |
| 100 < d ≤ 150 | 295 | 450–600 | 18 |
Hardness: Not hardness-specified; typically ~150–200 HB (informational). Value is in strength and −20 °C toughness.
S355J2 / St52 properties and conversion
International Equivalents
Values marked ≈ are nearest matches, not exact equivalents. Always confirm against the governing standard.
| System | Grade |
|---|---|
| EN | S355J2 |
| W.-Nr. (DIN) | 1.0577 |
| Eski DIN / Old DIN | St 52-3 N |
| ASTM | ≈ A572 Gr.50 / A709 Gr.50 |
| JIS | ≈ SM490B / SM490YB |
| GOST | ≈ 09Г2С (09G2S) |
| BS (UK) | ≈ 50B (S355) |
| GB (China) | ≈ Q355B |
Detailed comparison: S355J2 vs A572 Gr.50
Applications
- Heavy steel construction and bridges
- Crane and lifting equipment structures
- Offshore platforms
- Machinery chassis and booms
- Structural parts under pressure
- Mining and energy plant steelwork
Available Product Forms
Frequently Asked Questions
Are St52 and S355J2 the same steel?+
Yes. St52-3 is the old DIN 17100 designation; its current EN 10025-2 equivalent is S355J2, material number 1.0577. St52-3 N (normalized) corresponds exactly to S355J2. Only the designation changed — the material is the same.
What is the difference between S235 and S355?+
The key difference is yield strength: S235 minimum 235 MPa, S355 minimum 355 MPa — about 50% higher. S355 carries the same load in a thinner, lighter section, so it is preferred for bridges, cranes and heavy construction, while S235 is general-purpose and more economical.
What does 'J2' mean in S355J2?+
It is the Charpy impact test class: J2 means a minimum of 27 J at −20 °C. JR means 27 J at +20 °C and J0 at 0 °C. For cold climates or structures loaded at low temperature, J2 (or the stricter K2) is specified.
Is S355J2 weldable?+
Yes, readily. Its carbon equivalent is low (CEV ≤0.45), so it welds by all common processes without preheat in most sections. Very thick sections or highly restrained joints may benefit from mild preheat.
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References & Standards
Values on this page are reference data compiled from the applicable EN standard; certified material properties are defined by the mill test certificate (EN 10204 3.1).