Description
Factory-direct galvanized tube supply — XJY Structure integrates raw steel production and ERW fabrication under one roof, eliminating third-party sourcing gaps for Q235 and SS400 grades.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235 / SS400 Galvanized Square and Rectangular Steel Tube |
| Product Type | Galvanized Square and Rectangular Steel Tube (ERW) |
| Steel Grade | Q195, Q215, Q235, Q345, ASTM, SS400 |
| Standard | GB, API, CE, JIS |
| Section Shape | Square / Rectangular / Round |
| Size Range | 20×20 mm – 200×200 mm |
| Wall Thickness | 1.5 – 30 mm |
| Length | 1 – 12 m (standard 6 m / 6.4 m / 12 m; customizable) |
| Technique | ERW (Electric Resistance Welded) |
| Surface Treatment | Galvanized (Galvanized Coated) |
| Tolerance | ±5% |
| Ends | Plain (default) |
| Oiled or Non-oiled | Non-oiled |
| Application | Steel structures / Construction frames / Machinery / Scaffolding / Furniture / Fluid transport / Building frames |
| MOQ | 25 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Commercial Construction | Building frames, column-beam assemblies, roof trusses for warehouses and logistics centers |
| Industrial Facilities | Machinery frames, equipment support structures, platform walkways in processing plants |
| Infrastructure & Civil Works | Scaffolding systems, bridge handrails, sound barrier supports along highways |
| EPC & General Contracting | Prefabricated structural modules, mezzanine floors, stairway stringers for turnkey projects |
Where Galvanized Coating Thickness Decides Site Acceptance
Under-galvanized tubes fail third-party inspection and destroy project margins.
When structural contractors receive galvanized square and rectangular steel tubes with zinc coating below specification, the entire lot faces rejection — local re-galvanizing costs consume nearly all profit on the order. I learned this the hard way shipping a container of 100×100×4mm tubes to Dubai years back, where on-site testing revealed 45μm instead of the required 80μm minimum. Since then, coating thickness verification became non-negotiable at production and pre-loading stages. For buyers sourcing a galvanized square and rectangular steel tube supplier from China, the distance between factory and jobsite makes quality documentation and traceability the only shield against costly surprises. [NEED_CITE: EN 10219 cold-formed hollow section requirements]
Matching Structural Frames to Load-Bearing Specifications
Galvanized ERW tubes in Q235 and SS400 grades serve commercial buildings and industrial facilities where corrosion resistance meets moderate load demands. The 20×20 to 200×200 mm size range covers everything from light-duty furniture frames to heavy structural columns, while wall thickness from 1.5 to 30 mm allows engineers to optimize weight versus strength. Our integrated mill-to-fabrication model means the same quality system governs raw material chemistry and finished tube dimensions — no gaps in material certification chains when your galvanized square and rectangular steel tube arrives on site.
Engineering Compliance for International Projects
Structural hollow sections must satisfy project-specific codes: EN 10219 governs cold-formed welded sections in European markets, while ASTM A500 applies to North American construction. CE certification under EN 10210 or EN 10219 determines whether your shipment clears EU customs or faces rejection at the port. Steel grade equivalence matters — Q235 maps roughly to S235JR in EN standards and ASTM A500 Grade B, but chemical composition limits differ slightly. Our engineering team reviews shop drawings against applicable standards before production begins, flagging tolerance conflicts or welding procedure mismatches early. [NEED_CITE: steel grade equivalence between EN and ASTM standards]
Steel Grade Selection and ERW Welding Fundamentals
Q-series grades (Q195, Q215, Q235, Q345) follow Chinese GB standards where the number indicates minimum yield strength in MPa. SS400, a Japanese JIS grade, offers comparable tensile properties widely accepted across Southeast Asian and Middle Eastern projects. ERW (Electric Resistance Welded) processing uses high-frequency current to fuse the tube seam without filler metal, producing consistent weld quality suitable for structural applications up to moderate pressure ratings. Galvanized surface treatment — typically hot-dip coating — provides sacrificial corrosion protection for outdoor exposure, with coating thickness directly determining service life in humid or industrial atmospheres. The ±5% dimensional tolerance ensures fit-up accuracy for bolted or welded connections on structural frames.
Hidden Costs of Unverified Material Sources
Purchasing galvanized square and rectangular steel tubes from trading companies rather than integrated manufacturers creates three risk layers: material traceability gaps where heat numbers cannot be verified, coating thickness inconsistencies invisible until site inspection, and dimensional deviations that force costly rework during assembly. When certification documents lack chemical composition details or mechanical test results, third-party inspectors reject entire shipments. Projects face schedule delays, customs holds, and structural safety concerns when tubes fail to meet EN 10219 or ASTM A500 requirements. [NEED_CITE: structural steel fabrication quality control distance challenges]
Why Integrated Manufacturing Matters for Your Project
XJY Structure operates as the dedicated fabrication division of Shandong Xin Jiyuan Special Steel Tube Co., backed by our own steel mill with three production lines and over 2,800 specifications in raw material inventory. This vertical integration eliminates the gap between material supplier and fabricator — one source controls chemistry, one quality system governs production, one point of accountability handles your order. Our certified welding procedures (WPS/PQR) and qualified welders meet AWS and EN standards, while complete documentation packages include weld maps, dimensional inspection reports, and coating thickness measurements. We serve general contractors, EPC firms, and steel structure companies across the EU, Middle East, Southeast Asia, and Africa who need reliable fabrication partners in China.
Documentation & Compliance
- Mill Test Certificate documenting Q235 and SS400 chemical composition plus mechanical properties per GB standards
- CE certificate confirming EN 10210/EN 10219 compliance for European market structural applications
- ISO 9001 quality management certificate covering integrated steel production and fabrication processes
- SGS or BV third-party inspection reports verifying galvanized coating thickness and dimensional accuracy
- Full material traceability by heat number from our own steel mill through finished tube delivery
- Complete customs documentation including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- Galvanized tubes bundled with steel strips and edge protectors to preserve zinc coating during ocean transit
- Non-oiled surface condition ready for immediate welding or additional painting per project specifications
- Standard lengths of 6 m, 6.4 m, or 12 m optimized for 20ft and 40ft container loading efficiency
- Plain ends default configuration with custom cutting available per shop drawing requirements
- Heat number and steel grade stenciled on each tube for site identification and traceability verification
- FOB, CIF, or DDP shipping terms with professional oversized cargo loading and complete export documentation
Starting Your Procurement Process
Submit your project drawings (PDF/DWG), steel grade requirements, and target specifications to receive a detailed quotation within 24 hours, including material costs, fabrication charges, coating treatment, packing, and shipping estimates. Our engineering team prepares shop drawings for your review before production begins, ensuring dimensional accuracy and standard compliance. Confirm certification requirements and third-party inspection needs early to avoid documentation gaps during customs clearance.
Frequently Asked Questions
Q: What steel grade equivalence applies between Q235, SS400, and international standards?
A: Q235 (Chinese GB standard) offers comparable properties to S235JR (EN standard) and ASTM A500 Grade B, while SS400 (Japanese JIS standard) provides similar tensile strength widely accepted across Asian and Middle Eastern markets. Chemical composition limits vary slightly between standards, so project specifications determine which grade applies.
Q: Can you arrange third-party inspection before shipment?
A: Yes, we coordinate SGS, BV, or TUV inspection services to verify galvanized coating thickness, dimensional accuracy, and material certification before loading. Inspection reports become part of your complete documentation package for customs and project acceptance.
Q: What is the minimum order quantity for custom dimensions?
A: Standard MOQ is 25 tons for stock sizes. Custom non-standard dimensions or lengths require confirmation based on production scheduling and raw material availability — submit your specifications for a tailored assessment.
Q: How is galvanized coating thickness controlled and verified?
A: Hot-dip galvanizing follows project specifications for coating weight and thickness. We conduct mandatory coating checks at production completion and pre-loading stages, with measurements documented in inspection reports. Third-party verification available upon request.
Q: Do you provide shop drawing support and engineering coordination?
A: Our engineering team reviews your project drawings, prepares fabrication shop drawings for approval, and coordinates material optimization before production begins. This prevents dimensional errors and RFI delays that cause costly rework on site.
Get Your Galvanized Tube Quotation with Full Material Certification
Share your project specifications, steel grade requirements, and destination port to receive detailed pricing and mill test certificate samples. Contact XJY Structure at admin@xjystructure.com or WhatsApp +86 188 5315 7756 for engineering support and fabrication coordination.
