Grade Designations.
| BS EN 10025-2:2019 | S355J2 / 1.0577 |
| Sub-grade | J2 — Charpy impact tested at −20°C |
| ASTM approx | A572 Grade 50 |
| DIN | S355J2 / 1.0577 |
| Former BS | 50D (approx.) |
Availability & Supply Condition.
Bright Rounds: 10–80mm | Black Rounds: 25–400mm
Supply condition: Bright Drawn (cold drawn, h10 tolerance) or Hot Rolled Black (BS EN 10060 tolerances).
Cut to length from 1 piece — −0/+2mm standard tolerance — 2–3 day turnaround — Cutting service details ›
Chemical Analysis.
Values shown as percentages by weight (% wt). Values are ranges unless stated as maxima.
| Designation | C max | Si max | Mn max | P max | S max | N max |
|---|---|---|---|---|---|---|
| S355J2 (t≤16mm) | 0.20 | 0.55 | 1.60 | 0.025 | 0.025 | 0.012 |
| S355J2 (t>16–40mm) | 0.20 | 0.55 | 1.60 | 0.025 | 0.025 | 0.012 |
For full chemical analysis with heat number, request an EN 10204 3.1 material test certificate when ordering — available on all alloy grades. Certificate types explained ›
Mechanical Properties.
Values shown for standard supply condition. Properties vary by section size and heat treatment condition.
| Size (mm) | Yield Re (N/mm²) min | Tensile Rm (N/mm²) | A% min | Impact (J at −20°C) |
|---|---|---|---|---|
| ≤16 / >16–40 / >40–63 / >63–80 | ≥355 / ≥345 / ≥335 / ≥325 | 490–630 / 490–630 / 470–630 / 470–630 | 22 / 21 / 20 / 20 | ≥27 |
Hardness values: see our hardness conversion table to convert between HRC, HB, HV and tensile strength.
Typical Applications.
- Load-bearing shafts and axles
- Structural components and frames
- Heavy fabrications and welded assemblies
- Agricultural and plant machinery components
- Lifting and handling equipment
- Offshore and construction steelwork
Key Benefits.
- 355 N/mm² minimum yield — significantly stronger than S275
- Good weldability — no preheat required for most sections
- J2 sub-grade: guaranteed Charpy impact at −20°C
- Stocked as both bright and black bar
- Cost-effective step-up from mild steel
- Recognised globally — one of the most commonly specified structural grades
Remarks & Guidance.
Good weldability for sections to 25mm with standard electrodes above 5°C. For heavier sections or lower ambient temperatures, preheat to 50–100°C. S355 is a structural grade — not intended for precision machined components requiring tight tolerances or high-cycle fatigue applications. Specify an EN-series engineering steel for those applications. J2 designation confirms Charpy V-notch impact testing at −20°C: ≥27J minimum.
Relevant Heat Treatment Processes.
This grade responds to the following heat treatment processes. Click any card for temperatures, cooling methods and expected hardness values.
