Structural steel · EN 10025-2
S355JR
Also known as: 1.0045, S355
Overview
Workhorse European structural grade with higher yield than S235/S275; widely specified for beams, columns, and welded platework.
Typical supply: Plate, sections, hollow sections, bars
Mechanical Properties
Thermal Properties
For temperature derating, open Temperature Properties.
Physical Properties
Typical supply: Plate, sections, hollow sections, bars
Density 7850 kg/m³. Primary structural plate and sections.
Applications
- Primary structural members
- Crane runways and heavy frames
- Welded plate girders
- Mobile equipment chassis
Advantages
- Higher yield than S235/S275 for lighter primary members
- Widely specified for European beams, columns, and platework
- Good strength-to-cost for structural steelwork
Limitations
- Machinability moderate vs mild steel
- Coating required for corrosion protection
- Impact class JR for ambient service — check colder climates
Standards
- EN 10025-2 — Hot rolled products of structural steels
- Eurocode 3 — Design of steel structures (material properties)
Equivalent Materials
Electrical Properties
Chemical Composition
| Element | Min wt% | Max wt% | Typical wt% |
|---|---|---|---|
| C | — | 0.24 | 0.16 |
| Mn | — | 1.6 | 1.3 |
| P | — | 0.035 | — |
| S | — | 0.035 | — |
| N | — | 0.012 | — |
| Cu | — | 0.55 | — |
Typical / limit values for reference selection only — verify against mill certs for certified work.
Machinability
Machinability moderate; hardness rises with thickness and cooling rate after rolling.
Cost
Moderate premium over S235; often best strength-to-cost for European structural work.
Corrosion
Same coating practice as mild steel; JR impact class suited to ambient service.
- Indoor dryfair
- Outdoor paintedfair
- Marine atmospherepoor
For allowance / life screening, open Corrosion Allowance.