Description
Factory-Direct S255JR Supply — Every S255JR square steel tube ships with original mill test certificates and leaves our Jinan facility without middlemen markup.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | S255JR Square Steel Tube |
| Product Type | Square Steel Tube |
| Steel Grade | S255JR, Gr.B, S235, S235JR, S275, S355, STK400 |
| Standard | ASTM A500, ASTM A53, GB/T 3091, EN 10219 |
| Section Shape | Square |
| Size Range | 19mm × 19mm – 800mm × 800mm |
| Wall Thickness | 1 – 30 mm |
| Length | 5.8m – 12m / Random Length |
| Technique | ERW / Welded |
| Surface Treatment | Black Painting / Galvanized |
| Tolerance | ±1% |
| Ends | Plain |
| Packing | Bundles (below 8 inch) / Bulk (above 8 inch) |
| Application | Steel structures / Construction frames / Curtain wall / Support tubes / Fertilizer tube |
| MOQ | 5 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Building | Structural frames for warehouses, portal frames, mezzanine floors, column supports |
| Curtain Wall & Facade | Mullion tubes, transom members, cladding support grids |
| Industrial Structures | Machinery bases, conveyor frames, equipment support platforms |
| Agricultural & Greenhouse | Fertilizer tube structures, greenhouse skeleton frames, irrigation support |
Where Missing Mill Certificates Turn a Container into a Customs Hold
An S255JR square steel tube without traceable heat numbers is rejected at EU and Middle Eastern ports regardless of how competitive the price was.
Project procurement teams across Southeast Asia and the Gulf routinely report shipments held at destination because the supplier could not produce original mill test certificates matching the heat numbers stamped on the tubes. The S255JR square steel tube supplier who ships without EN 10219 or ASTM A500 compliance documentation forces the buyer to either arrange costly third-party re-testing at the port or face return freight. [NEED_CITE: EN 10219 cold-formed welded structural hollow sections certification requirements] Fragmented sourcing from multiple yards means certificates arrive in mixed formats, some missing chemical composition data — a gap that structural engineers will not sign off on.
Matching S255JR Square Steel Tube to Structural Frame and Curtain Wall Loads
The 19×19mm to 800×800mm side length range covers everything from light-duty curtain wall mullions to heavy portal frame columns. For building frames, the S255JR grade provides adequate yield strength for non-seismic zones while remaining weldable on-site without preheating. In curtain wall systems, the ±1% tolerance ensures that mullion-to-transom connections seat properly without shimming. The S255JR square steel tube in galvanized finish resists coastal and industrial atmospheric corrosion, extending maintenance cycles for facade structures exposed to salt-laden air.
Engineering Compliance and Surface Environment Selection
Structural frames designed to EN 1993 or AISC 360 require verified steel grade equivalence — S255JR maps directly to ASTM A500 Gr.B and Q235B for cross-standard substitution on international projects. [NEED_CITE: steel grade equivalence between EN 10219 and ASTM A500 specifications] For outdoor or high-humidity environments, galvanized coating provides sacrificial zinc protection; black painted finish suits indoor structural applications where appearance is secondary. The ERW welding process produces a consistent longitudinal seam that meets EN 10219 requirements for cold-formed structural hollow sections, and every batch undergoes three-stage in-house inspection covering dimensional, visual, and weld integrity checks. CE certification under EN 10210 and EN 10219 ensures European market customs clearance without additional conformity assessments.
Understanding ERW Welding, Grade Substitution, and Tolerance Implications
S255JR belongs to the EN non-alloy structural steel family, sitting between S235 and S275 in yield hierarchy — selecting the correct grade avoids both over-specification cost and under-performance risk. The ERW welded process forms the square profile from hot-rolled coil through progressive roll-forming and high-frequency resistance welding, producing a clean internal weld bead suitable for structural loads without the cost premium of seamless manufacturing. Wall thickness tolerance of ±1% means a 5mm nominal wall measures between 4.95mm and 5.05mm; buyers calculating theoretical weight must account for this band, as negative tolerance accumulation across long members affects both dead load estimates and connection design. [NEED_CITE: EN 10219 dimensional tolerance classes for cold-formed hollow sections] Surface treatment choice — galvanized for exterior corrosion resistance, black painted for interior economy, or bare for projects applying site-specific coating systems — should be confirmed before production to avoid rework.
The Hidden Cost of Unverified Steel Grade and Excessive Negative Tolerance
Substituting an unmarked tube labeled S255JR that actually tests as S235 reduces structural load capacity below design assumptions — a discrepancy discovered only during third-party inspection or, worse, after structural loading. Missing or mismatched mill certificates trigger port holds in the EU, Australia, and GCC countries, where customs authorities cross-check heat numbers against submitted documentation. [NEED_CITE: import compliance documentation requirements for structural steel in EU and GCC markets] Excessive negative tolerance — walls consistently at the lower band — compounds across hundreds of tons, reducing actual delivered weight against invoiced theoretical weight and eroding project material budgets. Rejection, re-testing, return freight, and project delay costs routinely exceed the initial price saving from unverified suppliers.
Why Project Buyers Source S255JR Square Steel Tube from Shandong Xin Jiyuan
Our Jinan facility operates three dedicated ERW production lines running simultaneously, delivering monthly capacity exceeding 20,000 tons across 2,800+ specifications — meaning your S255JR square steel tube order draws from ready stock or enters a production queue with typical lead times, not months-long waits. Factory-direct pricing eliminates trader margins, with volume discount programs reviewed every six months for recurring partners. Every heat carries original mill test certificates documenting chemical composition and mechanical properties, and SGS or BV third-party inspection is arranged on request before container sealing. CE certification covering EN 10210 and EN 10219, combined with ISO 9001:2015 registration, provides the documentation package European and Middle Eastern importers require for customs and project compliance. Our export team optimizes container loading for mixed-size orders, reducing per-ton freight costs on consolidated shipments.
Documentation & Compliance
- Mill test certificate documenting S255JR chemical composition (C, Mn, Si, P, S) and yield strength per EN 10219, linked to heat number stamped on each tube
- CE certificate covering EN 10210 (hot-finished) and EN 10219 (cold-formed) structural hollow sections for European market conformity
- ISO 9001:2015 quality management system certificate covering the full production and inspection workflow
- SGS or BV third-party inspection report available pre-shipment, covering dimensional verification, visual weld inspection, and coating thickness measurement
- Material traceability sheet mapping each bundle to its heat number, production date, and test certificate reference
- Export documentation package including packing list, bill of lading, certificate of origin, and commercial invoice formatted for destination customs
Packaging, Loading & Delivery
- ERW welded S255JR square tubes below 8 inch bundled with steel strips and edge protectors; tubes above 8 inch shipped in bulk loads secured with welded steel cradles
- Galvanized finish tubes receive additional polyethylene sleeve wrapping to prevent zinc coating abrasion during ocean transit and container handling
- Mixed-size container loading optimized for 20ft and 40ft containers, nesting smaller 19×19mm to 100×100mm sections inside larger 400×400mm to 800×800mm profiles to maximize payload per TEU
- Random length 5.8m and 12m tubes cut to project-specified lengths upon request, with cut ends deburred and marked with heat number and steel grade
- Each bundle tagged with waterproof label showing steel grade S255JR, size, wall thickness, heat number, gross/net weight, and destination mark
- FOB, CIF, and DDP terms available with door-to-door logistics coordination to major ports across Southeast Asia, Middle East, Africa, and South America
Requesting a Quotation with Mill Test Certificates
Submit your S255JR square steel tube requirements — side length, wall thickness, total tonnage, surface treatment preference, and destination port — via email or WhatsApp. Our team responds within 12 hours with factory-direct pricing, volume discount tiers, production lead time, and a sample mill test certificate from a recent heat for your engineer’s review.
Get Your S255JR Square Steel Tube Quote with Mill Certificates
Send your specification sheet to receive bulk pricing, available stock confirmation, and third-party inspection arrangement details.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.sdxinjiyuan.com
Mobile / WhatsApp / WeChat: +86 188 5315 7756
Email: admin@sdxinjiyuan.com
