Description
Factory-direct S355JR square steel tube — every batch shipped with original mill test certificates and EN10210/EN10219 compliance documentation for European customs clearance.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | S355JR Square Steel Tube |
| Product Type | Square / Rectangular Steel Tube (SHS / RHS) |
| Steel Grade | S235JR, S275JR, S355JR, S355J0, S355J2H, Q460, A36, SS400, ASTM A53 GR.B |
| Standard | EN10210, EN10219, ASTM A53, ASTM A500 |
| Section Shape | Square, Rectangular |
| Size Range | 15×15mm – 1000×1000mm (Square) / 20×30mm – 600×800mm (Rectangular) |
| Wall Thickness | 0.5mm – 50mm |
| Length | 5.8m – 14m or custom |
| Technique | ERW (Electric Resistance Welded), Hot Rolled |
| Surface Treatment | Bare / Oiled / Painted / Varnish / Galvanized / 3PE / Coating |
| Tolerance | ±1% |
| Ends | Plain / Cut / Threaded / Beveled / Flanged |
| Application | Steel structures / Construction frames / Machinery structure / Scaffolding / Furniture / Greenhouse / Building material / Low pressure fluid transport / Agriculture equipment |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Infrastructure | Building frames, scaffolding systems, urban civil construction structures, bridge support columns |
| Machinery & Equipment | Machine structure frames, agriculture equipment chassis, industrial fabrication bases |
| Commercial & Light Structural | Furniture frames, greenhouse structural supports, low-pressure fluid conveyance lines |
What Dimensional Tolerance Costs on a Structural Frame Order
A ±1% tolerance deviation on a 500×500mm S355JR square steel tube means 5mm of accumulated error across a multi-story frame — enough to force on-site rework or reject an entire batch at inspection.
Global buyers sourcing structural hollow sections from fragmented suppliers routinely face specification gaps when non-standard dimensions fall outside catalog offerings. Custom orders then carry extended lead times and inflated minimums, while inconsistent wall thickness across batches creates load-bearing uncertainty on project sites. The result is delayed handovers, re-fabrication costs, and customs holds when mill certificates fail to match shipped material [NEED_CITE: EN 10219 cold-formed hollow section dimensional tolerance requirements].
How S355JR Square Steel Tube Matches Structural Engineering Demands
S355JR square steel tube delivers the yield strength tier that structural engineers specify for load-bearing frames in commercial buildings and industrial facilities. The ERW hot-rolled production process maintains ±1% dimensional tolerance across side lengths from 15×15mm up to 1000×1000mm, ensuring that connection plates and bolt holes align without forced fitting. Wall thickness options from 0.5mm to 50mm cover everything from light greenhouse framing to heavy machinery base structures, while surface treatments — bare, galvanized, 3PE coated, or painted — address corrosion exposure from indoor environments to outdoor coastal sites.
Engineering Compliance and Certification Requirements
Structural hollow sections destined for European markets must conform to EN 10210 for hot-finished or EN 10219 for cold-formed requirements, with chemical composition and mechanical properties verified through original mill test certificates [NEED_CITE: EN 10210 hot-finished structural hollow sections compliance]. For North American projects, ASTM A500 and A53 grade equivalencies require cross-referencing documentation that traces each heat number to its test report. Surface treatment selection — hot-rolled bare for indoor structural use, galvanized for outdoor exposure, 3PE for buried or submerged applications — directly affects service life and maintenance intervals. Custom cut-to-length orders at 5.8m to 14m reduce on-site welding and secondary processing, while beveled or threaded ends prepare tubes for direct mechanical connection.
Steel Grade Selection and ERW Welding Process
The S-series steel grades — S235JR, S275JR, S355JR, S355J0, S355J2H — represent incrementally higher minimum yield strength, with S355JR providing the balance of formability and load capacity that dominates structural specifications worldwide. The J0 and J2H suffixes indicate Charpy impact testing at 0°C and -20°C respectively, critical for projects in cold climates where brittle fracture risk increases. Q460 from the Chinese GB system and A36 from ASTM offer regional equivalencies, though project engineers must verify chemical composition compatibility before substitution. ERW welding produces a longitudinal seam with dimensional accuracy superior to seamless alternatives at comparable wall thicknesses, making it the dominant process for square and rectangular hollow sections in the 0.5mm to 50mm range [NEED_CITE: ERW versus seamless steel tube manufacturing process comparison].
Hidden Costs of Incorrect Grade or Missing Certification
Specifying S235JR when structural calculations demand S355JR creates a load capacity deficit that only surfaces during inspection — after fabrication is complete and material is already on site. Missing or incomplete mill test certificates trigger customs holds at destination ports, with demurrage charges accumulating while documentation disputes resolve. Wall thickness below the specified tolerance — even within acceptable manufacturing variance — reduces the section modulus and compromises the load rating that structural engineers calculated. These failures trace back to suppliers who cannot provide heat-number traceability or who blend grades across production batches without disclosure [NEED_CITE: steel grade equivalence between EN and ASTM standards for structural applications].
Why Source S355JR Square Steel Tube From Our Production Lines
Three dedicated ERW production lines running simultaneously deliver monthly capacity exceeding 20,000 tons, with factory-direct pricing that eliminates intermediary markups for volume buyers. Our in-house laboratory conducts three-stage inspection covering chemical composition, mechanical properties, and dimensional verification — every batch ships with original mill test certificates traceable to specific heat numbers. The inventory spans 2,800+ specifications across square, rectangular, and round profiles, enabling consolidated container loading that mixes structural tubes with plates and sections in a single shipment. Sharp-corner 90° square tube capability serves architectural applications where precise corner geometry matters for aesthetic and connection requirements. Lloyd’s CE certification under EN 10210/EN 10219 and FPC factory production control satisfy European market compliance, while SGS or BV third-party inspection arranges on request before container sealing.
Documentation & Compliance
- Mill test certificate documenting S355JR chemical composition and mechanical properties per EN10219, traceable to individual heat numbers
- CE certificate confirming EN10210/EN10219 compliance for structural hollow sections entering European Union markets
- ISO 9001:2015 quality management certificate covering the full production and inspection process
- SGS or BV third-party inspection report available on request, conducted before shipment at our facility
- Material traceability documentation linking each bundle to its heat number, production date, and test results
- Complete customs documentation package including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- S355JR square steel tubes bundled with steel strips and edge protectors, preserving surface finish whether bare, oiled, or galvanized during ocean transit
- Container loading plans optimized for side lengths from 5.8m to 14m, with heavy-wall sections positioned at the base and lighter profiles stacked above to prevent deformation
- Galvanized S355JR square steel tube shipments include separation layers between bundles to prevent zinc coating damage from friction during transport
- Heat number and steel grade markings stenciled on each bundle, matching the mill test certificate for on-site verification
- FOB, CIF, and DDP shipping terms available, with professional export documentation handling customs clearance at destination ports
- Custom cut-to-length orders at specified dimensions reduce on-site cutting waste and accelerate project assembly timelines
Start Your S355JR Square Steel Tube Procurement
Submit your specification requirements — side dimensions, wall thickness, steel grade, quantity, and destination port — via email or messaging to receive a competitive bulk quotation within 12 hours. We provide mill test certificates, third-party inspection coordination, and container loading optimization as standard parts of the procurement process, not as premium add-ons.
Request Your S355JR Square Steel Tube Quotation Today
Send your project specifications to admin@sdxinjiyuan.com or contact us via WhatsApp at +86 188 5315 7756 to receive pricing, mill test certificate samples, and delivery timelines for your S355JR square steel tube requirements.
Frequently Asked Questions
Q: What is the steel grade equivalence between S355JR and ASTM standards?
A: S355JR roughly corresponds to ASTM A572 Grade 50 in yield strength, though chemical composition differs slightly. We provide cross-reference documentation and mill test certificates that support customs clearance and engineering approval for projects requiring ASTM equivalency verification.
Q: Can I order non-standard dimensions outside your catalog range?
A: Yes. Our three production lines handle custom sizes within the 15×15mm to 1000×1000mm square and 20×30mm to 600×800mm rectangular range, with wall thickness from 0.5mm to 50mm. Minimum order quantity is 1 ton for trial orders, with typical production lead times for custom specifications.
Q: What documentation accompanies each shipment?
A: Every batch ships with original mill test certificates showing chemical composition and mechanical properties, traceable to specific heat numbers. CE certificates for EN10210/EN10219 compliance, packing lists, bills of lading, and certificates of origin are included. SGS or BV third-party inspection reports arrange on request before shipment.
Q: How do you handle container loading for mixed-size orders?
A: Our export team creates detailed loading plans that position heavy-wall and large-dimension S355JR square steel tubes at the container base, with lighter profiles stacked above using separation materials. This prevents deformation during ocean transit and maximizes container utilization for cost efficiency.
Q: What surface treatment options are available for S355JR square steel tube?
A: We offer bare, oiled, painted, varnished, galvanized, 3PE coated, and custom coating options. Surface treatment selection depends on your application environment — galvanized for outdoor corrosion resistance, 3PE for buried or submerged conditions, and bare or oiled for indoor structural use where painting occurs on site.
