Description
Factory-Direct Pricing, Zero Middlemen — As a vertically integrated mill and fabricator, XJY Structure produces Q235, Q345, S355JR hot dip galvanized square tubes from our own steel, cutting material markups entirely.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Hot Dip Galvanized Square Tube EN 10219 |
| Product Type | Square Steel Tube (Hollow Section) |
| Steel Grade | Q195, Q235, Q345, SS400, S355JR |
| Standard | EN 10219, EN 10210, ASTM A53, ASTM A500, ASTM A36, BS 1387, ISO 65, JIS G3444, GB/T 3091, GB/T 13793 |
| Section Shape | Square |
| Size Range | 21.3 mm – 660 mm (1/2″ – 26″) |
| Length | 5.8 m / 6 m / 11 m or as required |
| Technique | ERW / Welded |
| Surface Treatment | Hot Dip Galvanized (Zinc Coated 40–600 g/m²) |
| Tolerance | ±1% |
| Pipe Ends | Plain / Beveled / Threaded / Grooved |
| Processing Services | Decoiling, Bending, Cutting, Punching, Welding |
| Application | Steel structures, Agricultural greenhouses, Construction frames, Fluid transport, Industrial facilities, Infrastructure projects |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Agricultural Engineering | Greenhouse skeleton frames, irrigation support structures, livestock shelter roofing purlins |
| General Construction | Building column and beam frames, mezzanine platforms, stairway handrails |
| Industrial Facilities | Warehouse portal frames, conveyor support structures, equipment mounting bases |
| Infrastructure Projects | Sound barrier posts, lighting pole foundations, bridge access walkways |
| EPC & Steel Structure Contractors | Prefabricated modular frames, connection assemblies, bracing systems |
Where Zinc Coating Thickness Decides Whether Your Shipment Clears Site Inspection
A 15-micron shortfall on hot dip galvanized square tubes can stall an entire project at destination port.
I still remember a Southeast Asian greenhouse order that sat in Jakarta for three weeks because the zinc coating came in at 45 microns instead of the specified 60. The buyer had to arrange local re-galvanizing at triple the original coating cost — and we absorbed the loss. That kind of gap between supplier promise and actual delivery is exactly what the Hot Dip Galvanized Square Steel Tube EN 10219 Supplier designation is meant to eliminate. When fabrication is outsourced overseas, buyers cannot walk the production floor to verify coating thickness, dimensional accuracy, or weld seam quality. Material traceability breaks down when fabricators source steel from third-party mills without heat-number linkage. [NEED_CITE: EN 10219 cold-formed hollow section dimensional and coating requirements]
Matching Galvanized Square Tubes to Structural and Corrosive Environments
Hot dip galvanized square tubes in Q235 and S355JR grades serve projects where both structural load-bearing and long-term atmospheric corrosion resistance are non-negotiable. The zinc coating range of 40–600 g/m² allows specification matching — light indoor frames may require only 40 g/m², while outdoor greenhouse structures in tropical coastal zones demand 275 g/m² or higher for 20-year service life. Our vertically integrated production means the same quality system governs raw steel chemistry, ERW welding, and galvanizing bath temperature control, so coating adhesion remains consistent across every length.
Engineering Compliance Across EN, ASTM, and GB Frameworks
Structural engineers specifying Hot Dip Galvanized Square Steel Tube EN 10219 products for EU-bound projects require CE marking and full compliance with EN 10219 dimensional tolerances and S355JR mechanical delivery conditions. North American EPC firms ordering the same cross-section under ASTM A500 need mill test certificates referencing Grade B or C yield criteria. Chinese domestic infrastructure tenders often call for Q345 per GB/T 3091. The critical procurement question is not whether the tube looks right — it is whether the documentation package satisfies the engineer of record and the customs authority at destination. [NEED_CITE: steel grade equivalence mapping between EN 10219 S355JR and ASTM A500 Grade C]
Steel Grade Selection and ERW Welding Process Fundamentals
The Q-series (Q195, Q235, Q345) follows the Chinese yield-strength naming convention, where Q235 indicates a minimum yield of 235 MPa — directly comparable to S235JR in the European EN 10219 system. S355JR offers higher yield strength for heavier structural frames, while SS400 serves general Japanese-spec industrial applications. All grades listed are produced via ERW (Electric Resistance Welding), a process where the steel strip is cold-formed into square profile and the longitudinal seam is fusion-welded under pressure without filler metal. ERW delivers tighter dimensional tolerance than SSAW for smaller square sections, and the weld seam is fully normalized during the hot dip galvanizing bath cycle, eliminating residual stress concentrations at the joint. The ±1% tolerance on side length ensures that connection plates and bolt-hole patterns fabricated at our workshop align precisely at site — a detail that matters when a 660 mm square column must mate with a pre-drilled base plate.
The Hidden Cost of Accepting Unverified Coating and Untraceable Material
Procuring Hot Dip Galvanized Square Steel Tube EN 10219 products from traders who cannot provide heat-number-linked mill test certificates creates compounding risk. If the zinc coating falls below project specification, the entire batch may fail third-party SGS or BV inspection at destination — triggering re-galvanizing costs, demurrage charges, and schedule delays that dwarf the original material savings. If the steel grade cannot be traced to a specific heat, structural engineers may reject the shipment outright, forcing emergency re-procurement from alternative sources at premium pricing. [NEED_CITE: consequences of non-compliant zinc coating thickness in hot dip galvanized structural steel]
Why Project Procurement Teams Source Directly from XJY Structure
XJY Structure operates as the dedicated fabrication division of Shandong Xin Jiyuan Special Steel Tube Co., Ltd., meaning every Hot Dip Galvanized Square Steel Tube EN 10219 order is fulfilled from our own steel mill through our own fabrication workshop — one material source, one quality system, one point of accountability. Our in-house理化实验室 issues mill test certificates covering chemical composition and mechanical properties for every heat, with full traceability from slab to finished galvanized tube. We hold CE certification under EN 10219 and EN 10210 for EU market compliance, and routinely accommodate SGS, BV, and TÜV third-party inspections before container sealing. With over 2,800 specifications in raw material inventory, we can fulfill mixed-size container loads without forcing buyers to meet impractical single-SKU minimums. Our fabrication workshop provides CNC cutting, bending, punching, and welding to engineering drawings — so buyers receive finished, drill-ready components rather than raw lengths requiring secondary processing at site.
Documentation & Compliance
- Mill Test Certificate documenting Q235 / Q345 / S355JR chemical composition and mechanical properties per EN 10219, linked to individual heat numbers
- CE Certificate confirming EN 10219 and EN 10210 compliance for EU market structural steel procurement
- ISO 9001 Quality Management System certificate covering the full production chain from steelmaking to hot dip galvanizing
- SGS or BV third-party inspection report verifying zinc coating thickness (40–600 g/m²) and dimensional tolerance (±1%) prior to shipment
- Material traceability documentation mapping each bundle to its originating heat number and galvanizing batch
- Complete customs export package including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- Hot dip galvanized square tubes bundled with steel strips and fitted with edge protectors to preserve the zinc coating during ocean transit and handling
- Seaworthy packaging with waterproof wrapping for 5.8 m / 6 m / 11 m lengths, optimized for 20ft and 40ft container loading configurations
- Zinc coating surface protected by passivation treatment to prevent white rust formation during extended shipping and storage periods
- Custom cut-to-length service available per engineering drawings, with bundle labeling showing steel grade, size, heat number, and coating class
- Heat number and steel grade (Q235 / Q345 / S355JR) stenciled on each bundle for site identification and inspection traceability
- FOB, CIF, and DDP shipping terms available with professional oversized cargo loading and lashing planning for heavy-wall square sections
How to Initiate Your Procurement Inquiry
Submit your project drawings (PDF or DWG), required steel grades, coating thickness specification, target standards (EN 10219 / ASTM A500 / GB/T 3091), and destination port — our engineering team responds within 24 hours with a detailed quotation including material, fabrication, coating, packing, and freight costs, along with a shop drawing timeline and production schedule. For non-standard dimensions or custom fabrication requirements, share your connection detail drawings and we will provide a fabrication feasibility assessment with material optimization recommendations.
Request Your Quotation and Mill Test Certificate
Send your specifications, steel grade requirements, and target quantity to receive a detailed quotation with full material traceability documentation.
Tel: +86 531 8573 6315 | Mobile/WhatsApp/WeChat: +86 188 5315 7756 | Email: admin@xjystructure.com
Frequently Asked Questions
Q: What is the difference between EN 10219 S355JR, ASTM A500 Grade C, and GB Q345B — which standard should my project specify?
A: These three grades represent equivalent yield strength categories across European, American, and Chinese standards. S355JR per EN 10219, ASTM A500 Grade C, and Q345B per GB/T 3091 all deliver minimum yield strength in the 345–355 MPa range. The correct choice depends on your project’s governing engineering code and the destination country’s customs and inspection requirements. Our team can provide grade equivalence mapping and issue mill test certificates referencing the standard your engineer of record requires.
Q: How does hot dip galvanized coating compare to pre-galvanized coating for outdoor structural applications?
A: Hot dip galvanized coating immerses the finished tube in a molten zinc bath, producing a metallurgically bonded coating of 40–600 g/m² that covers all surfaces including the interior. Pre-galvanized tubes are manufactured from pre-coated strip, resulting in thinner zinc layers (typically 20–40 g/m²) and exposed bare steel at cut edges. For greenhouse frames, infrastructure posts, and industrial structures exposed to atmospheric corrosion, hot dip galvanized square tubes deliver significantly longer service life.
Q: Can you produce non-standard square tube dimensions, and what is the minimum order quantity?
A: Yes, our fabrication workshop can produce custom sizes outside the standard 21.3 mm – 660 mm range based on your engineering drawings. Custom lengths, cut-to-size, and secondary processing (punching, bending, welding) are all available. The standard MOQ is 1 Ton, and we can accommodate mixed-size container loads from our inventory of over 2,800 specifications.
Q: What quality documentation do you provide for EU and Middle East projects?
A: For EU projects, we provide CE marking certification under EN 10219 and EN 10210, mill test certificates with full heat-number traceability, and dimensional and coating inspection reports. For Middle East and other regions, we accommodate SGS, BV, and TÜV third-party inspections prior to shipment. Our complete export documentation package includes packing list, bill of lading, and certificate of origin.
Q: What are the available shipping terms and typical production lead times?
A: We offer FOB, CIF, and DDP shipping terms with professional loading and lashing planning for oversized and heavy cargo. Production lead times depend on order volume and customization requirements — standard sizes from stock ship faster, while custom fabrication and coating orders follow the approved shop drawing schedule. We provide full container tracking until site delivery.
