Description
Factory-direct pricing with full mill certification — Q235 galvanized ERW square and rectangular steel tubes shipped with original test certificates and CE/ISO documentation for smooth customs clearance.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | ASTM Q235 Galvanized ERW Square/Rectangular Steel Pipe |
| Product Type | Galvanized ERW Square and Rectangular Steel Tube |
| Steel Grade | Q195, Q215, Q235, Q345, ASTM, S235, SS400 |
| Standard | GB, API, CE, JIS, ISO 9001, SGS |
| Section Shape | Square, Rectangular, Round |
| Size Range | 20×20 mm – 200×200 mm |
| Wall Thickness | 1.5 – 30 mm |
| Length | 1 – 12 m (customizable) |
| Technique | ERW (Electric Resistance Welded) |
| Surface Treatment | Galvanized Coated |
| Tolerance | ±5% |
| Ends | Plain / as required |
| Processing Service | Welding, Punching, Cutting, Bending, Decoiling |
| Invoicing | By Actual Weight |
| Packing | Customized / Export standard packing |
| MOQ | 25 Tons (one 20ft container) |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Infrastructure | Building frames, scaffolding systems, bridge support structures |
| Industrial Fabrication | Machinery frames, conveyor structures, mining equipment supports |
| Energy & Fluid Transport | Gas pipelines, hydraulic systems, boiler piping, oil transport lines |
| Electrical & Utility | Power transmission towers, electrical installation conduits |
| Chemical & Fertilizer | Chemical fertilizer piping, corrosion-resistant process lines |
Why Galvanized Coating Thickness Determines Whether Your Container Clears Customs
A zinc coating below contract specification means rejection at the job site — not at the mill gate.
Buyers across Southeast Asia and the Middle East regularly face delays when galvanized coating fails field verification. Port inspectors and project engineers measure zinc thickness on arrival, and anything below the contracted micron level triggers full-container rejection. The cost is not just the coating — it is return freight, re-galvanizing, and weeks of schedule slip on an active construction timeline. [NEED_CITE: hot-dip galvanized coating thickness standards for structural steel] As a Galvanized ERW Square Rectangular Steel Pipe supplier, we measure every batch before loading and ship with original mill certificates documenting coating weight and adhesion results.
Matching Wall Thickness and Section Size to Structural Load Requirements
For structural frames and scaffolding, the 20×20 mm to 200×200 mm section range with wall thickness from 1.5 mm to 30 mm covers everything from light-duty electrical conduit supports to heavy-load bearing columns. The ERW welding process produces a consistent longitudinal seam suitable for pressures typical in fluid transport and structural applications. Galvanized surface treatment adds corrosion resistance for outdoor and humid environments without requiring field painting. Our production lines run these Galvanized ERW Square Rectangular Steel Pipe specifications in continuous batches, so a single container can mix section sizes to match a bill of materials without splitting orders across suppliers.
Engineering Compliance and Certification Requirements Across Markets
Structural projects in the EU require CE-marked hollow sections conforming to EN 10210 or EN 10219, while North American buyers reference ASTM A500 for structural tubing. Middle East and African infrastructure projects often accept GB-standard Q235 and Q345 grades with mill test certificates, but increasingly request third-party inspection before shipment. [NEED_CITE: steel grade equivalence between GB Q235 and international standards] The Galvanized ERW Square Rectangular Steel Pipe we supply carries ISO 9001:2015 production certification, CE EN 10210/10219 marking where applicable, and original mill test certificates per heat number. For buyers who need SGS or BV third-party inspection, we arrange testing before container loading so documentation travels with the cargo.
Understanding Q235 and Cross-Grade Equivalence for Procurement
Q235 is China’s most widely used carbon structural steel, with yield behavior comparable to S235 in the European EN system and roughly aligned with ASTM A36 in North America. [NEED_CITE: steel grade equivalence standards between GB, EN, and ASTM] The Q-series (Q195, Q215, Q235, Q345) follows the Chinese GB standard naming convention where the number indicates minimum yield strength in MPa. SS400 from the Japanese JIS system and S235 from the European EN system serve similar structural roles but differ in chemical composition limits and testing protocols. ERW welding suits these grades well because the carbon equivalent stays within weldable ranges, and the galvanized coating bonds effectively to the clean steel surface produced after welding and cooling. Wall thickness tolerance of ±5% means actual weight may vary from theoretical calculations — this matters when invoicing is by actual weight and when structural engineers calculate load capacity from nominal dimensions.
Hidden Costs of Procuring the Wrong Grade or Missing Documentation
Ordering Q235 when the project spec calls for Q345 means lower yield strength on site — a difference that does not show up in visual inspection but fails structural load testing. Shipping without original mill test certificates causes customs holds in markets that require material traceability documentation. [NEED_CITE: customs documentation requirements for steel imports] Galvanized ERW Square Rectangular Steel Pipe with incomplete or missing CE marking cannot be used on EU-regulated construction projects regardless of actual material quality. Negative tolerance beyond acceptable limits reduces actual wall thickness below design assumptions, creating structural safety concerns and potential liability for the procurement team. These are not theoretical risks — they represent real project delays, re-shipment costs, and in some cases, structural remediation expenses that dwarf the original material savings from choosing an unverified supplier.
Why Buyers Choose Our Mill for Galvanized ERW Square Rectangular Steel Pipe
We operate three production lines in Jinan with monthly capacity exceeding 20,000 tons, meaning your order runs on our own equipment rather than being brokered through trading companies. Every heat of steel we process goes through our in-house laboratory for chemical composition and mechanical testing, with results documented on original mill test certificates that travel with each shipment. Our inventory covers 2,800+ specifications across square, rectangular, and round sections, so standard sizes ship from stock while custom lengths and non-standard dimensions run on typical production lead times. We hold CE EN 10210/10219, ISO 9001:2015, and FPC certifications, and we arrange SGS or BV third-party inspection on request before container sealing. For buyers placing recurring orders, we offer volume-based pricing reviews every six months and consolidated multi-product container loading to reduce per-ton freight costs.
Documentation & Compliance
- Mill test certificate documenting Q235 chemical composition and mechanical properties per GB standard, issued per heat number
- CE certificate covering EN 10210 hot-finished and EN 10219 cold-formed hollow sections for EU market compliance
- ISO 9001:2015 quality management system certificate covering production lines and inspection processes
- SGS or BV third-party inspection report verifying galvanized coating thickness, dimensional tolerance, and surface quality before loading
- Material traceability records linking each bundle to heat number, production date, and test certificate
- Full customs documentation package including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- Galvanized ERW square and rectangular tubes bundled with steel strips and edge protectors to preserve the zinc coating during ocean transit
- Seaworthy packaging with waterproof wrapping for 1–12 m lengths, customized to container dimensions for 20ft and 40ft loading
- Container loading plans optimized for 20×20 mm to 200×200 mm sections, mixing sizes to maximize weight utilization per shipment
- Custom cutting to project-specific lengths available, reducing on-site waste and secondary processing for construction buyers
- Heat number and steel grade marked on each bundle for site identification and traceability verification
- FOB, CIF, and DDP shipping terms available with professional export documentation handling
Start Your Procurement With Verified Specifications
Send your requirements — section size, wall thickness, steel grade, quantity, and destination port — and receive a quotation with volume pricing, delivery timeline, and sample mill test certificate within 12 hours. For non-standard dimensions or mixed-size container orders, we provide loading optimization and consolidated pricing across product categories.
Request Quotation and Mill Test Certificate
Submit your specifications via email at admin@sdxinjiyuan.com or contact us on WhatsApp at +86 188 5315 7756 to begin your order.
Frequently Asked Questions
Q: What is the difference between Q235, S235, and SS400 steel grades?
A: Q235 follows the Chinese GB standard, S235 follows European EN standards, and SS400 follows Japanese JIS standards. All three serve similar structural applications with comparable yield behavior, but chemical composition limits and testing protocols differ by standard system. We supply all three grades and can provide cross-reference documentation for your project specification.
Q: What documents do I need for customs clearance when importing galvanized steel tubes?
A: Most markets require original mill test certificates showing chemical composition and mechanical properties, a certificate of origin, packing list, and bill of lading. EU markets additionally require CE marking per EN 10210 or EN 10219. We provide complete documentation packages and can arrange third-party inspection reports if your importer or project owner requires independent verification.
Q: Can I order non-standard sizes or mixed specifications in one container?
A: Yes. Our inventory covers 2,800+ specifications, and we support consolidated container loading mixing square, rectangular, and round sections in different sizes. MOQ is 25 tons for a 20ft container, and we accommodate trial orders for new buyers before committing to full-container volumes.
Q: How do you ensure galvanized coating quality before shipment?
A: Every batch undergoes coating thickness testing in our in-house laboratory, with results documented on the mill test certificate. We can arrange SGS or BV third-party inspection before container loading if your project requires independent verification. Coating thickness and adhesion results travel with the shipment documentation.
Q: What is the typical production lead time for custom lengths or non-standard dimensions?
A: Standard sizes ship from ready stock, while custom lengths and non-standard dimensions run on typical production lead times depending on order volume and specification complexity. We confirm exact timelines after reviewing your requirements and can accommodate urgent orders for buyers with active project schedules.
Get Factory-Direct Pricing With Full Certification
Email your specifications to admin@sdxinjiyuan.com or message +86 188 5315 7756 on WhatsApp to receive your quotation and mill test certificate sample.
