Description
Direct Mill Supply with Full Heat-Number Traceability — Every Hot Dipped Galvanized Square and Rectangular Steel Tube we ship carries an EN 10204 3.1 Mill Test Certificate tied to the original coil heat number, because our own steel mill produces the raw material before it ever reaches the ERW line.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Galvanized Square and Rectangular Steel Tube |
| Product Type | Square / Rectangular Steel Tube (SHS / RHS) |
| Steel Grade | Q195, Q215, Q235, Q345, GR.A, GR.B, S235, S355 |
| Standard | ASTM A213, DIN EN 10217-1 |
| Section Shape | Square / Rectangular |
| Size Range | Outer diameter or side length as customer request (OEM ODM) |
| Wall Thickness | 0.8 mm – 20 mm |
| Length | 500 mm / 1000 mm / 4000 mm / 5800 mm / 11800 mm or customized |
| Technique | ERW (Welded) |
| Surface Treatment | Pre-galvanized / Hot-dip galvanized / Bare / Oiled / Black steel original |
| Processing Service | Welding, Punching, Cutting, Bending, Decoiling |
| Packing | Standard Seaworthy Packing |
| Delivery Time | 15-20 days |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Solar Energy | Solar power stents and mounting frames requiring long-term outdoor corrosion resistance |
| Industrial Construction | Warehouse structural frames, portal steel frames, mezzanine platforms |
| Building Construction | Steel columns, beams, and bracing members for commercial buildings |
| Infrastructure | Steel fence posts, highway guardrail posts, signage support structures |
| General Structure | Load-bearing SHS/RHS for modular structures and equipment skids |
Why Galvanizing Thickness Decides Whether Your Steel Fence Lasts Five Years or Twenty-Five
Coating mass, not just coating presence, separates field-acceptable galvanized tubes from premature-rust failures.
I once watched an entire container of hot-dip galvanized square tubes get rejected at a Middle Eastern solar site because the zinc layer measured 45 microns instead of the specified 65 microns. The salt-spray test failed within weeks. That kind of failure does not show up at the loading port — it shows up six months later when the client’s inspector pulls out an elcometer on site. When you source a Hot Dipped Galvanized Square and Rectangular Steel Tube through a trader who sub-contracts galvanizing to a third-party dip shop, there is no single party accountable for coating consistency. Our integrated line measures film thickness on every tube before it leaves the zinc bath, and anything below spec goes straight back for re-dipping. [NEED_CITE: hot-dip galvanizing coating thickness standards for structural steel]
Matching Wall Thickness and Steel Grade to Structural Load Paths
A solar mounting frame carrying static panels in a coastal environment needs a different combination than a warehouse portal frame bearing crane loads. For solar stents, Q235 or S235 grade paired with hot-dip galvanizing provides adequate yield strength and 25-year corrosion protection in most atmospheric conditions. When the Hot Dipped Galvanized Square and Rectangular Steel Tube is used in warehouse columns or heavy-load beams, Q345 or S355 grades deliver the higher yield strength that structural engineers specify under EN 1993 or AISC load combinations. The ERW welding process we use produces a consistent longitudinal weld seam suitable for both light-gauge purlins and heavier structural hollow sections up to 20 mm wall thickness.
Engineering Code Compliance Across EN, ASTM, and GB Designations
Structural projects rarely stay within a single national standard. A European EPC contractor working in Southeast Asia may need S355 material that also satisfies ASTM A500 Grade C equivalence for local inspection approval. The steel grades we stock — Q195 through Q345 in the GB system, S235 and S355 in the EN system, plus GR.A and GR.B — cover the most commonly requested cross-references in international tenders. [NEED_CITE: steel grade equivalence between EN, ASTM, and GB standards for structural hollow sections] Hot-dip galvanizing to ISO 1461 or ASTM A123 ensures the coating meets whichever standard the project specification calls for. Custom cut-to-length, punching, and bending services mean the tubes arrive on site ready to bolt or weld, reducing secondary fabrication costs at the project location.
How ERW Welding and Zinc Coating Interact in Structural Tubes
The ERW (Electric Resistance Welding) process forms the square or rectangular profile from steel coil by passing it through forming rolls and welding the seam through resistive heating — no filler metal, no flux. This produces a clean, consistent weld line that accepts zinc coating uniformly during hot-dip galvanizing, provided the weld zone is properly cleaned before immersion. Pre-galvanized tubes, by contrast, are made from already-coated coil and then formed; the zinc layer at the weld seam is thinner and more vulnerable to corrosion over time. For outdoor applications like solar stents and fence posts, hot-dip galvanizing of the finished tube provides complete zinc coverage including the weld zone, which is why engineers specify it for 25-year design life structures. Wall thickness tolerance directly affects both theoretical weight pricing and actual structural capacity — negative tolerance within standard limits is normal practice, but excessive thinning compromises load-bearing performance. [NEED_CITE: ERW welded hollow section manufacturing process and galvanizing compatibility]
The Real Cost of Accepting Sub-Standard Mill Test Documentation
Buying a Hot Dipped Galvanized Square and Rectangular Steel Tube without verified MTCs tied to heat numbers creates a chain of liability gaps. When a customs inspector at an EU port requests EN 10204 3.1 documentation and the supplier can only provide a trader-issued certificate, the shipment gets held — sometimes for weeks. On site, if the engineer discovers that the zinc coating thickness does not match the project specification, the entire batch may need replacement at the supplier’s cost, but only if the original contract included enforceable coating requirements backed by testable standards. [NEED_CITE: EN 10204 inspection document types for steel products] Material traceability from coil heat number through ERW forming to hot-dip galvanizing eliminates this exposure entirely.
Why Procurement Teams Choose an Integrated Mill-to-Tube Supplier
Our own steel mill produces the raw coil that becomes every Hot Dipped Galvanized Square and Rectangular Steel Tube we deliver — there is no gap between material supplier and fabricator. This vertical integration means we control chemical composition from the melt shop, wall thickness at the ERW line, and zinc coating mass at the galvanizing bath, all under one ISO 9001 quality system. We stock over 2,800 specifications covering the full range of square and rectangular sizes, so your project does not wait for a third-party mill to roll your order. Every shipment includes complete documentation: WPS records, weld maps, dimensional inspection reports, and coating thickness measurements. Our engineering team reviews shop drawings before production begins, catching dimension conflicts before they become field rework. We have delivered structural steel to projects across the EU, Middle East, Southeast Asia, and Africa, and our loading teams plan container stowage to maximize weight utilization while protecting the galvanized surface during ocean transit.
Documentation & Compliance
- Mill Test Certificate (EN 10204 3.1) documenting Q235/S355 chemical composition, yield strength, and tensile properties per heat number
- CE certificate confirming EN 10210 / EN 10219 compliance for structural hollow sections exported to European markets
- ISO 9001:2008 quality management system certificate covering the full production chain from steelmaking to galvanizing
- SGS or BV third-party inspection report verifying coating thickness, dimensional tolerance, and visual quality before shipment
- Full material traceability linking each Hot Dipped Galvanized Square and Rectangular Steel Tube bundle to its original coil heat number
- Complete customs documentation package: packing list, commercial invoice, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- Hot-dip galvanized SHS/RHS bundles secured with steel strips and edge protectors to prevent zinc coating damage during handling and ocean transit
- Pre-galvanized and bare tubes packed with anti-rust oil and waterproof wrapping to preserve surface condition in humid shipping environments
- Container loading plans optimized by side length and wall thickness to maximize tonnage per 20ft or 40ft container while maintaining bundle integrity
- Custom cut-to-length service available for 500 mm to 11800 mm lengths, with each bundle clearly marked with heat number, steel grade, and dimensions
- FOB, CIF, and DDP shipping terms supported with door-to-door logistics coordination for project sites worldwide
Start Your Inquiry with Drawings and Get a Complete Quote Within 24 Hours
Send your project drawings in PDF or DWG format along with the required steel grade, surface treatment preference, and total quantity. We respond within one business day with a detailed quotation covering material, fabrication, galvanizing, packing, and shipping costs — plus a shop drawing timeline and production schedule. If your project requires non-standard lengths, hole patterns, or specific coating thickness, our engineering team will confirm feasibility before you commit.
Request Your Hot Dipped Galvanized SHS/RHS Quotation Today
Submit your specifications and receive a full quotation with Mill Test Certificate samples within 24 hours.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.xjystructure.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@xjystructure.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
