Square Hollow Section Tube S355J2H

Square/Rectangular steel tube( Black;black annealed; galvanized)
Size: 10*10mm- 500*500mm
Thickness:0.8mm-60mm
Length: 5.8m/6m/12m ....
We offer S355J2H structural hollow sections, manufactured according to EN 10219-1 (cold formed) / EN 10210-1 (hot finished). This is a high-strength steel with a minimum yield strength of 355 MPa and guaranteed impact toughness of 27J at -20°C, ensuring excellent performance for load-bearing structures even in cold environments. It features low carbon content (max 0.22%) for superior weldability. Available in Circular, Square, and Rectular sections, supplied with EN 10204 3.1 Mill Certificates
Grade S355J2H
Garde
The designation S355J2H follows a standardized nomenclature defined by the European standards (EN).
S =Structural Steel (used for load-bearing applications).
355 = Minimum Yield Strength(in MPa). This indicates that the steel has a minimum yield strength355 MPafor thicknesses up to 16mm.
J2 =Impact Test Requirement. This specifies that the material must undergo a Charpy V-notch impact test at a temperature-20°C, with a minimum average energy absorption of 27 Joules . This is a key selling point for cold-weather applications.
H = Hollow Section. This denotes that the steel is intended for the production of hollow profiles (tubes), distinguishing it from standard plate or sheet grades
Key Standards: EN 10210 vs. EN 10219
When trading S355J2H, you must specify the manufacturing standard, as it defines the production method and tolerances.
Standard | Full Name | Manufacturing Process | Key Feature for Clients |
EN 10210-1 | Hot finished structural hollow sections | Hot forming (with or without subsequent heat treatment) | Generally lower residual stresses; often preferred for welding and dynamic loading. |
EN 10219-1 | Cold formed welded structural hollow sections | Cold forming (welded) | Tighter dimensional tolerances; often more cost-effective for standard sections |
Note: Both standards cover the same S355J2H grade chemistry and mechanical properties, but the dimensional tolerances and delivery conditions differ slightly
Chemical Composition
Chemical
Element | Percentage (%) | Implication for Trade |
Carbon (C) | ≤ 0.22 | Low carbon content ensures excellent weldability without preheating in most sections. |
Silicon (Si) | ≤ 0.55 | Used for deoxidation (killing) of the steel. |
Manganese (Mn) | ≤ 1.60 | Adds strength and hardness. |
Phosphorus (P) | ≤ 0.030 | Kept low to maintain ductility. |
Sulfur (S) | ≤ 0.030 | Kept low to prevent brittleness. |
Carbon Equivalent (CEV) | ≤ 0.45 | Crucial for welding. This value helps the client determine welding parameters to avoid cracking |
Mechanical Properties
These are the guaranteed values you will certify in your Mill Test Certificate (EN 10204 3.1 or 3.2)
Strength and Ductility | ||
Property | Value | Condition |
Yield Strength (ReH) | ≥ 355 MPa | For wall thickness (T) ≤ 16mm. |
| ≥ 345 MPa | For T > 16mm to ≤ 40mm. |
Tensile Strength (Rm) | 470 - 630 MPa | For wall thickness ≥ 3mm to ≤ 40mm. |
| 510 - 680 MPa | For wall thickness < 3mm. |
Elongation (A) | ≥ 20% | Minimum percentage after fracture |
Toughness (Impact Resistance) | |
Property | Value |
Test Temperature | -20°C |
Minimum Impact Energy | 27 Joules (average for 3 specimens, 10x10mm sample) |
Common Applications
Construction:Columns, trusses, frames, piling, scaffolding
Mechanical Engineering:Agricultural machinery, truck/trailer frames, cranes
Renewable Energy:Support structures for solar trackers and carports
