S235JR / S275JR / S355JR Cold Formed Welded Hollow Section

S235JR / S275JR / S355JR Cold Formed Welded Hollow Section is a family of structural steel tubes manufactured to European standards through cold forming and high-frequency welding. These hollow sections offer excellent strength-to-weight ratios and consistent mechanical properties for modern construction applications. Unlike the ASTM A106 Gr B Seamless Carbon Steel Pipe designed for high-temperature pressure fluids, these cold formed sections serve structural frameworks where dimensional precision and weldability matter most.

Product Parameters

Square size range: 20mm x 20mm to 400mm x 400mm. Regular square sizes include 40×40, 50×50, 60×60, 80×80, 100×100, 120×120, 150×150, 200×200, 250×250, 300×300 mm . Rectangular size range: 30mm x 20mm to 400mm x 300mm. Wall thickness: 2.0mm to 16.0mm. Common thicknesses: 2.0, 2.5, 3.0, 4.0, 5.0, 6.0, 8.0, 10.0, 12.0 mm . Length: 6 meters, 12 meters standard, with custom lengths up to 18 meters available . Processing technique: Cold forming followed by high-frequency induction welding . Execution standards: EN 10219-1 and EN 10219-2 for cold formed welded structural hollow sections . Packaging: Seaworthy bundles with steel strips, waterproof wrapping, and edge protectors. Surface treatment: Black bare, oiled, painted, galvanized, or as requested.

Chemical Composition (Typical %)

S235JR:
Carbon (C): 0.17 max
Manganese (Mn): 1.40 max
Phosphorus (P): 0.035 max
Sulfur (S): 0.035 max
Silicon (Si): 0.35 max

S275JR:
Carbon (C): 0.21 max
Manganese (Mn): 1.50 max
Phosphorus (P): 0.035 max
Sulfur (S): 0.035 max
Silicon (Si): 0.35 max

S355JR:
Carbon (C): 0.24 max
Manganese (Mn): 1.60 max
Phosphorus (P): 0.035 max
Sulfur (S): 0.035 max
Silicon (Si): 0.55 max

Physical Properties (for thickness ≤16mm)

S235JR: Yield Strength 235 MPa minimum, Tensile Strength 360-510 MPa, Elongation 24% minimum
S275JR: Yield Strength 275 MPa minimum, Tensile Strength 430-580 MPa, Elongation 20% minimum
S355JR: Yield Strength 355 MPa minimum, Tensile Strength 510-680 MPa, Elongation 20% minimum
Carbon Equivalent (CEV): 0.35-0.45 max depending on grade
Impact Testing: 27J at room temperature for JR grades

Product Applications

Building construction frameworks, columns, and trusses . Bridge components and infrastructure projects. Industrial platforms and walkways. Mechanical engineering for agricultural machinery and equipment . Truck and trailer manufacturing. Renewable energy structures including solar panel supports . Furniture frames and architectural metalwork.