Description
Factory-direct S355JR sharp corner rectangular steel tube supplier — 41 invention patents covering sharp-corner forming technology, with 2,800+ specifications in stock for immediate dispatch.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | S275JR / S355JR Sharp Corner Square & Rectangular Steel Tube |
| Product Type | Square and Rectangular Steel Tube (Sharp Corner / Right-Angle) |
| Steel Grade | S235JR, S275JR, S355JR, S355J2H, S355J0, Q460, A36, SS400, ASTM A53 GR.B |
| Standard | EN10210, EN10219, ASTM A53 |
| Section Shape | Square / Rectangular (Sharp Corner 90°) |
| Size Range | 15×15 mm – 1000×1000 mm (Square) / 20×30 mm – 600×800 mm (Rectangular) |
| Wall Thickness | 0.5 mm – 50 mm |
| Length | 5.8 m – 14 m or custom |
| Technique | Hot Rolled Carbon Steel Welded (ERW) |
| Surface Treatment | Galvanized / 3PE / Painting / Coating Oil / Bare / Varnish |
| Tolerance | ±1% |
| Ends | Plain ends / Cutting / Threading / Beveled / Flange |
| Application | Steel structures / Urban and civil construction / Machine structure / Agriculture equipment / Greenhouse / Scaffolding / Building material / Furniture / Low pressure fluid transport |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Facade & Curtain Wall | Architectural steel framing for glass curtain walls, building exterior cladding systems |
| Construction | Structural columns, beam-to-column connections, bridge handrails, infrastructure supports |
| Steel Structure Fabrication | Precision cut-to-length tubes for welded frame assembly, truss members |
| Machinery Manufacturing | Conveyor frames, equipment bases, hydraulic support structures |
| Agriculture | Greenhouse structural frames, irrigation support systems |
Where EN10219 Certification Decides Customs Clearance for Your S355JR sharp corner rectangular steel tube supplier Order
Missing CE documentation under EN 10219 blocks EU port clearance — regardless of product quality.
I have watched containers sit in Rotterdam for weeks because the mill test certificate referenced the wrong standard clause, or the CE mark cited EN 10210 when the procurement spec demanded EN 10219. The tubes were structurally sound. The paperwork was not. For S355JR and S355J2H grades exported to European markets, the declaration of performance must align with EN 10219-1 technical delivery conditions and EN 10219-2 dimensional tolerances. [NEED_CITE: EN 10219 cold-formed welded structural hollow sections certification requirements] Buyers specifying S275JR or S355JR under EN 10219 need to verify that the supplier holds Lloyd’s or equivalent notified body certification for these specific grades — not just a generic ISO 9001 certificate.
How Sharp-Corner Geometry Matches Facade Engineering Requirements
Architectural curtain wall framing demands tubes that sit flush against glass panel mounting brackets without visible gaps. Standard ERW rectangular tubes produce corner radii of R≥2t, creating uneven contact surfaces that force fabricators to grind or shim on site. Our patented sharp-corner forming process achieves true 90-degree edges across wall thicknesses from 0.5 mm to 50 mm, eliminating secondary machining for facade contractors. The S355JR sharp corner rectangular steel tube supplier capability covers 2,800+ specifications, meaning non-standard sizes like 450×250×12 mm can be produced without minimum order penalties that typically apply at trading companies.
Structural Compliance and Surface Protection for Site Conditions
Load-bearing frames in civil construction must satisfy EN 1993 Eurocode 3 or AISC 360 depending on the project region. S355JR and S355J2H grades provide the yield strength baseline for these calculations, with J2H designation confirming -20°C Charpy impact toughness for cold-climate installations. [NEED_CITE: steel grade equivalence between EN 10219 and ASTM A500 standards] For outdoor exposure, hot-dip galvanized coating delivers corrosion resistance without field painting, while 3PE coating suits buried or submerged applications. Wall thickness tolerance of ±1% ensures that theoretical weight calculations match actual delivered mass — critical when structural engineers specify members by kg/m rather than piece count.
Steel Grade Selection and ERW Welding Process Explained
The S-series grades (S235JR, S275JR, S355JR, S355J2H) follow the EN 10219 / EN 10025 naming convention where the number indicates minimum yield strength in MPa for thickness ≤16 mm. Q460 represents the Chinese GB/T 1591 equivalent high-strength low-alloy grade. ASTM A53 GR.B serves North American projects requiring imperial unit documentation. All grades listed are produced via ERW (electric resistance welding), where the longitudinal seam is formed by passing current through the heated strip edges under pressure — suitable for structural hollow sections up to 600×800 mm rectangular and 50 mm wall thickness. The sharp-corner forming occurs after welding, using calibrated roller dies that bend the flat sides into 90-degree angles without stretching the outer fiber beyond the material’s elongation limit. This is why corner radius consistency holds across the full length of each tube.
The Hidden Cost of Substituted Corner Radii and Grade Mismatches
A Lagos high-rise project once received standard rectangular tubes instead of specified sharp-corner sections. The facade contractor discovered the R≥3t corners only after cutting 200 pieces for curtain wall framing. Every piece required re-welding of mounting brackets, adding three weeks to the critical path. Similarly, S275JR material shipped with an MTC claiming S355JR chemistry fails independent lab re-test at destination — triggering full container rejection under EN 10219-2 clause 8 inspection protocols. [NEED_CITE: structural steel material substitution consequences in construction projects] The cost is never the tube price difference. It is crane idle time, re-fabrication labor, and delayed handover penalties.
Procurement Confidence from Factory-Controlled Verification
As the original Chinese inventor of sharp-corner rectangular tubes with 41 invention patents, we control the entire production chain from coil slitting to final bundling. Our in-house physical and chemical laboratory tests every heat number for tensile strength, yield point, elongation, and chemical composition before release — the mill test certificate you receive reflects actual batch data, not template values. Full international certification includes ISO 9001:2015, Lloyd’s CE marking under EN 10210 and EN 10219, Singapore FPC for Southeast Asian projects, and SGS/BV third-party inspection available at our Jinan facility prior to container sealing. With 2,800+ specifications covering square sections up to 1000×1000 mm and rectangular up to 600×800 mm, we consolidate tube and section steel orders (H-beam, channel, angle) into single shipments — reducing your supplier count and freight cost.
Documentation & Compliance
- Mill test certificate documenting S355JR or S275JR chemical composition and mechanical properties per EN 10219-2, traceable to heat number
- CE certificate issued by Lloyd’s Register covering EN 10210 and EN 10219 for S235JR through S355J2H grades
- ISO 9001:2015 quality management system certificate valid for sharp-corner rectangular tube production
- SGS or BV third-party inspection report available for pre-shipment dimensional and visual verification
- Material traceability sheet linking each bundle to heat number, production date, and test results
- Export customs documents including packing list, bill of lading, and certificate of origin formatted for destination country requirements
Packaging, Loading & Delivery
- S355JR sharp corner rectangular steel tubes bundled with galvanized steel strips at 1.5 m intervals, with hardwood saddles preventing corner deformation during transit
- Galvanized surface tubes wrapped with PE film at welding seam positions to protect zinc coating from abrasion against adjacent pieces
- Container loading optimized for 5.8 m and 11.8 m lengths to maximize 20ft and 40ft OT utilization, with sharp-corner orientation preventing point-load damage to container floor
- Custom cut-to-length service available for 14 m maximum, with beveled or threaded ends prepared per drawing before bundling
- Each bundle tagged with heat number, steel grade (S355JR / S275JR), size designation, and PO reference for site identification
- FOB Jinan/Qingdao, CIF destination port, or DDP door delivery arranged with forwarders experienced in structural steel documentation
Start Your S355JR sharp corner rectangular steel tube supplier Inquiry
Submit your dimension schedule (outer size × wall thickness × length), steel grade requirement, surface treatment preference, and destination port. We respond within 12 hours with unit pricing, mill test certificate template, and production lead time. For non-standard sizes outside the 2,800+ specification range, custom tooling quotes are provided within 48 hours.
Request Quotation and Mill Test Certificate
Send your inquiry to admin@sdxjypipe.com or contact via WhatsApp at +86 188 5315 7756 with your specification list.
Frequently Asked Questions
Q: What is the corner radius difference between sharp-corner and standard rectangular tubes per EN 10219?
A: Standard EN 10219 rectangular tubes have external corner radii of R≥2t (twice the wall thickness), meaning a 10 mm wall tube has minimum 20 mm radius corners. Our patented sharp-corner process achieves R≤1.5t for most sizes, with true 90-degree edges available for architectural applications where flat-to-flat contact is required for bracket mounting or glass cladding frames.
Q: How do I specify S355JR under EN 10219 when my drawing references ASTM A500 Gr.C?
A: S355JR per EN 10219 and ASTM A500 Gr.C are not direct equivalents — S355JR requires minimum 355 MPa yield for thickness ≤16 mm, while A500 Gr.C requires 345 MPa yield for all thicknesses. For European projects, specify EN 10219 S355JR directly. For North American projects requiring ASTM compliance, we produce to A500 Gr.B or Gr.C with matching chemistry and provide both EN and ASTM mill test certificates.
Q: Can you produce non-standard sizes like 450×250×12 mm rectangular sharp-corner tubes?
A: Yes. Our 3 production lines cover 2,800+ specifications including off-standard dimensions. For sizes outside the standard range (15×15 to 1000×1000 mm square, 20×30 to 600×800 mm rectangular), custom tooling is fabricated in-house. MOQ for custom sizes is 1 ton, with typical production lead time of 15–25 days after deposit confirmation.
Q: What surface treatment is recommended for S355JR sharp-corner tubes used in coastal construction?
A: For marine or high-humidity environments, hot-dip galvanized coating (minimum 70 μm zinc thickness per EN ISO 1461) provides long-term corrosion protection without maintenance. For buried applications or chemical exposure, 3PE (three-layer polyethylene) coating offers superior barrier protection. Bare or oiled finish suits indoor structural applications where field painting will be applied after fabrication.
Q: Do you provide CE certification for EN 10219 S355JR tubes exported to EU countries?
A: Yes. We hold Lloyd’s Register CE certification covering EN 10210 and EN 10219 for steel grades S235JR through S355J2H. Each shipment includes the CE declaration of performance, mill test certificate with EN 10219-2 compliance statement, and factory production control documentation required for EU customs clearance and construction product regulation compliance.
