S235JR / S355JR Seamless Carbon Steel Round Tubes

In the industrial and construction sectors, every steel pipe carries a mission of safety and engineering precision. Our S235JR / S355JR seamless carbon steel round tubes are manufactured in strict compliance with EN 10210 / EN 10297 standards. Using high-purity continuously cast round billets and formed via hot-rolling or cold-drawing in a single pass, these pipes are free from weld seams and feature a homogeneous, dense grain structure. They are the ideal base material for fluid conveyance, structural support, and mechanical fabrication.

S235JR – General-purpose mild carbon structural steel (equivalent to Q235B). Offers excellent cold formability, weldability, and machining plasticity. Suitable for general load-bearing members, building frames, and non-critical pressure applications. Cost-effective and a long-standing stock item for engineering warehouses.

S355JR – High-strength low-alloy structural steel (equivalent to Q355B). Minimum yield strength ≥355 MPa, approximately 50% higher than S235JR. Delivers greater load capacity with the same wall thickness, enabling lightweight design. Ideal for bridges, towers, heavy machinery, and dynamic loads in cold climates.

Process: Hot-rolled (OD > 114mm) or cold-drawn (OD ≤ 114mm), with smooth internal and external surfaces and dimensional tolerances meeting EN 10279 class.

Lengths: Standard fixed lengths of 5.8m, 6m, 12m, or custom lengths per customer drawings.

Wall Thickness: Our products are available in a wide range of wall thicknesses, covering low to medium-high pressure system requirements.

End Finishes: Plain ends, beveled ends, or threaded, compatible with welding, grooved, and flanged connections.

●  Construction steel structures: scaffolding, grid frames, truss columns

●  Mechanical manufacturing: hydraulic cylinders, conveyor rollers, drive shafts

●  Fluid conveyance: water, oil, and gas pipeline systems

●  Photovoltaic / wind power: support foundations and ground piles

Every batch undergoes chemical composition analysis, tensile testing, flattening tests, and hydrostatic non-destructive inspection. EN 10204 Type 3.1 or 3.2 material certificates are available, ensuring full traceability from raw material to final delivery.

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