Description
Factory-Direct Galvanized ERW Square Rectangular Steel Tube Supplier — Every batch tested in-house for zinc coating thickness and dimensional tolerance before container loading.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Galvanized ERW Square/Rectangular Steel Tube |
| Product Type | Galvanized Square and Rectangular Steel Tube |
| Steel Grade | Q195, Q215, Q235, Q345, ASTM, S235, SS400 |
| Standard | GB, ASTM, API, CE, JIS, ISO 9001 |
| Section Shape | Square / Rectangular / Round |
| Size Range | 20×20 mm – 200×200 mm |
| Wall Thickness | 1.5 – 30 mm |
| Length | 1 – 12 m (also 5.8 m / 6 m / 6.4 m) |
| Technique | ERW (Electric Resistance Welded) |
| Surface Treatment | Galvanized Coated |
| Tolerance | ±5% |
| Ends | Plain / Customizable |
| Application | Structural frames, Construction, Bridge, Machinery, Fluid transport |
| MOQ | 25 Tons (one 20ft container) |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Architecture | Building frames, glass curtain wall supports, architectural facades using sharp-corner rectangular tubes |
| Machinery & Equipment | Hydraulic cylinder housings, conveyor structures, machinery frames requiring precision dimensions |
| Infrastructure & Energy | Bridge handrails, oil & gas pipeline supports, renewable energy mounting structures |
| Industrial Piping | Fluid transport lines, chemical fertilizer processing pipes, gas distribution networks |
Where Galvanized Coating Thickness Decides Site Acceptance
A 45-micron zinc layer instead of 80 microns means the entire container gets rejected at the port.
I once handled a galvanized square tube order for a Middle East contractor. The zinc coating came in at 45 microns instead of the specified 80. The client’s SGS inspector caught it at the port, and a full 20-foot container had to be re-galvanized at our cost. That scar taught me: galvanized structural pipes demand coating verification before loading, not after. Sourcing a Galvanized ERW Square Rectangular Steel Tube Supplier who tests every batch in-house eliminates this risk entirely. [NEED_CITE: hot-dip galvanized coating thickness standards for structural steel]
Matching Structural Load Requirements in Curtain Wall Framing
Galvanized ERW square and rectangular steel tubes from 20×20 mm to 200×200 mm with wall thickness up to 30 mm provide the dimensional precision needed for glass curtain wall connections. The sharp-corner technology we pioneered ensures flat bearing surfaces that eliminate gaps at welded joints, reducing field rework. For facade contractors working across 50+ countries, consistent corner quality and full certification packages mean the tubes arrive ready for installation without secondary machining.
Engineering Compliance Across GB, ASTM, and EN Standards
Structural hollow sections used in load-bearing frames must comply with project-specific engineering codes. Our Galvanized ERW Square Rectangular Steel Tube production meets GB, ASTM, API, CE, and JIS requirements, with equivalent grade cross-referencing available for Q235/S235/ASTM A500 conversions. Third-party inspection by SGS or BV confirms chemical composition and mechanical properties before shipment, ensuring customs clearance in EU and regulated markets. [NEED_CITE: EN 10219 cold-formed structural hollow section dimensional tolerances]
Understanding ERW Welding and Galvanized Surface Protection
Electric Resistance Welding produces a uniform weld seam with consistent strength across the tube perimeter, making ERW tubes suitable for structural framing where seam integrity matters. Hot-dip galvanizing applies a zinc coating that provides sacrificial corrosion protection, extending service life in outdoor and humid environments. The non-oiled finish we deliver is ready for welding or painting without surface preparation. Wall thickness tolerance of ±5% ensures theoretical weight calculations match actual delivered weight, preventing cost overruns on tonnage-based contracts.
The Hidden Cost of Unverified Zinc Coating and Negative Tolerance
Ordering galvanized tubes without pre-shipment coating verification risks rejection at destination ports, triggering re-galvanizing costs and project delays. Negative tolerance beyond ±5% reduces actual wall thickness, compromising structural load capacity and failing engineering inspections. Missing or incorrect Mill Test Certificates block customs clearance in EU markets requiring CE marking under EN 10210/EN 10219. [NEED_CITE: consequences of non-compliant steel tube imports in regulated markets]
Why Project Procurement Teams Choose Our Mill
We operate three production lines covering 2,800+ specifications, eliminating the need to source from multiple suppliers for different tube sizes. Our in-house physical and chemical laboratory tests every batch for zinc coating thickness, dimensional accuracy, and mechanical properties before dispatch. The 41 invention patents we hold include China’s first sharp-corner rectangular tube technology, filling gaps in architectural applications where corner quality matters. Full international certifications—ISO 9001:2015, Lloyd’s CE (EN 10210/10219), Singapore FPC, and SGS/BV verification—ensure smooth customs clearance across 50+ export destinations. Professional container loading with anti-damage measures prevents bending and surface scratches during ocean transit.
Documentation & Compliance
- Mill Test Certificate documenting Q195–Q345 chemical composition and yield strength per GB/T 6728
- CE certificate confirming compliance with EN 10210/EN 10219 for EU market customs clearance
- ISO 9001:2015 quality management system certificate covering production and testing processes
- SGS or BV third-party inspection report verifying zinc coating thickness and dimensional tolerance
- Material traceability by heat number linking each tube to its production batch and test results
- Customs documents including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- Galvanized tubes bundled with steel strips and edge protectors to preserve the zinc coating during ocean transit
- Surface protection through non-oiled finish ready for immediate welding or painting at project site
- Container loading optimized for 20ft and 40ft shipments with 25-ton MOQ matching standard freight capacity
- Custom cutting to 5.8 m / 6 m / 6.4 m lengths available to match project specifications and reduce on-site waste
- Heat number and steel grade marking on each tube for traceability and inspection verification
- FOB, CIF, and DDP shipping terms with professional loading supervision to prevent transit damage
Submit Specifications for Quotation and Mill Test Certificate
Provide your required dimensions, steel grade, surface treatment, quantity, and destination port to receive a detailed quotation within 12 hours. We will include Mill Test Certificate samples, third-party inspection options, and container loading plans tailored to your project timeline.
Get Your Galvanized ERW Square Rectangular Steel Tube Quote
Submit your specifications and destination to receive pricing, certification documents, and delivery timeline.
Company: Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.sdxjypipe.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@sdxjypipe.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
Frequently Asked Questions
Q: How do Q235, S235, and ASTM A500 grades compare for structural applications?
A: Q235 (GB), S235 (EN), and ASTM A500 Grade B are equivalent structural grades with similar yield strength requirements. We provide cross-reference documentation to ensure correct material selection for your project specifications and local engineering codes.
Q: Can you provide Mill Test Certificates and arrange third-party inspection?
A: Yes, every shipment includes a Mill Test Certificate documenting chemical composition and mechanical properties. We arrange SGS, BV, or Lloyd’s surveyor inspection upon request to verify zinc coating thickness and dimensional tolerance before loading.
Q: Do you produce non-standard dimensions and what is the minimum order quantity?
A: We produce custom non-standard sizes beyond the 20×20 mm to 200×200 mm range with wall thickness up to 30 mm. The minimum order quantity is 25 tons (one 20ft container), with typical production lead times for custom specifications.
Q: What are the differences between galvanized, hot-rolled, and oiled surface finishes?
A: Hot-dip galvanized coating provides sacrificial corrosion protection for outdoor and humid environments. Hot-rolled finish offers a mill scale surface suitable for painting. Non-oiled galvanized finish is ready for welding without surface preparation, while oiled finish provides temporary rust prevention during storage and transit.
Q: Do your products carry CE marking and comply with EN 10210/EN 10219 for EU markets?
A: Yes, our Galvanized ERW Square Rectangular Steel Tube production holds Lloyd’s CE certification under EN 10210/EN 10219, ensuring compliance with European structural hollow section standards for customs clearance and project acceptance in EU member states.
Request Your Galvanized ERW Square Rectangular Steel Tube Quotation
Send your specifications, steel grade, and destination port to receive pricing and certification documents within 12 hours.
Company: Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.sdxjypipe.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@sdxjypipe.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
