Description
Factory-Direct Galvanized Square Steel Tube — Every batch of Q235B GI tube ships with original mill test certificates and is produced on our own ERW lines in Jinan, eliminating middleman markups on bulk orders.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235B Galvanized Square Steel Tube |
| Product Type | Galvanized Square and Rectangular Steel Tube |
| Steel Grade | Q235, Q345, Q195, Q215 |
| Standard | BS, EN, GB, AISI, ASTM, DIN, JIS |
| Section Shape | Square / Rectangular |
| Size Range | 10mm – 1000mm (side length) |
| Wall Thickness | 0.6mm – 28mm |
| Length | 1m – 12m |
| Technique | ERW (Hot Rolled / Cold Rolled) |
| Surface Treatment | Galvanized (Zinc Coating 30–275g/m²), Black, Color Painting, PVC Coated |
| Tolerance | ±1% |
| Ends | Plain, Beveled, Threaded with Couplings/Sockets |
| Application | Steel structures, construction frames, machinery, bridges, pressure vessels |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Building | Scaffolding uprights, curtain wall support frames, mezzanine columns |
| Infrastructure | Bridge handrail posts, solar panel mounting structures, industrial platform beams |
| Machinery & Equipment | Conveyor system frames, machine base supports, crane boom sections |
| General Engineering | Warehouse racking uprights, fencing posts, equipment guardrails |
What Missing Mill Certificates Cost You at Customs
A container of galvanized square steel tube without traceable mill test certificates can be held at port for weeks — or rejected outright.
I have seen importers in Southeast Asia and South America lose an entire shipment to customs holds simply because the supplier could not produce heat-number-linked test reports. When you source a Galvanized Square Steel Tube from a fragmented supply chain, the risk of mixed heats, unverified zinc coating weights, and missing CE or ISO paperwork is real. [NEED_CITE: EN 10219 cold-formed hollow section compliance requirements for structural steel imports] Without original mill certificates, your project engineer cannot sign off on material compliance, and your customs broker cannot clear the cargo.
How This GI Tube Matches Structural Frame Requirements
The Q235B grade delivers adequate yield strength for light-to-medium structural frames, while the galvanized zinc coating at 30–275g/m² provides corrosion protection for both indoor and outdoor exposure. Our ERW process ensures consistent weld seam quality across the full 10mm–1000mm size range, and the ±1% tolerance keeps connection points aligned on-site. As a Galvanized Square Steel Tube supplier running three production lines, we hold ready stock in standard sizes and can roll custom non-standard dimensions within typical production lead times.
Engineering Compliance and Certification Path
For European projects, our galvanized tubes conform to EN 10219 cold-formed welded hollow section requirements, and we carry CE certification under EN 10210/EN 10219. [NEED_CITE: steel grade equivalence between GB Q-series and EN S-series structural standards] North American buyers can request material graded to ASTM A500. Every Galvanized Square Steel Tube we ship includes three-stage in-house inspection — dimensional check, weld seam verification, and coating weight measurement — before the container is sealed.
Steel Grade Selection and ERW Process Logic
Q235 sits in the mild carbon steel range, offering good weldability and formability for general structural use. Q345 steps up the yield strength for heavier load-bearing frames without sacrificing field weldability. The ERW process we use produces a longitudinal weld seam through resistance welding, then the entire tube is cold-formed and sized for dimensional accuracy. For galvanized tubes, the black tube is first formed and welded, then hot-dip galvanized to achieve the specified zinc coating — this sequence ensures the coating covers both the base metal and the weld zone uniformly. Wall thickness tolerance at ±1% means you receive the structural capacity you designed for, not a theoretical number inflated by negative tolerance stacking.
Hidden Costs of Sourcing the Wrong Grade or Coating
Specifying Q195 when the structural drawing calls for Q345 will fail engineering inspection and require full replacement — not a partial fix. Ordering a zinc coating below 60g/m² for an outdoor application in a coastal environment leads to premature white rust and red rust, triggering warranty claims and re-procurement costs. [NEED_CITE: galvanized coating weight selection guidelines for different corrosion environments] Missing or forged mill certificates create liability exposure: if a structural member fails and the material cannot be traced back to a verified heat, the entire project faces legal and insurance complications.
Why Importers Choose Xin Jiyuan for Galvanized Square Steel Tube
We operate three ERW production lines in Jinan with a combined monthly capacity exceeding 20,000 tons, meaning your Galvanized Square Steel Tube order is manufactured in-house — not brokered through a trading desk. Our inventory covers 2,800+ specifications across square, rectangular, and round profiles, so standard sizes ship from stock while custom orders are scheduled on our own lines. Every batch carries original mill test certificates linked to heat numbers, and we welcome SGS or BV third-party inspection at our facility before loading. For long-term partners, 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 Q235B chemical composition and mechanical properties per GB/T 6728, linked to heat number
- CE certificate covering EN 10210 and EN 10219 for European structural hollow section compliance
- ISO 9001:2015 quality management certificate covering full production and inspection process
- SGS or BV third-party inspection report available upon request for independent quality verification
- Material traceability report mapping each tube bundle to its original heat number and galvanizing batch
- Full customs document package: commercial invoice, packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- Q235B galvanized square tubes bundled with steel strips and edge protectors to preserve the zinc coating during ocean transit
- Seaworthy packaging with waterproof wrapping for 6m and 12m lengths, stacked in layers with timber separators
- Container loading plan optimized per size range — smaller sections nested to maximize 20ft and 40ft HC payload
- Cut-to-length service available within the 1m–12m range, with cut ends deburred and re-galvanized if required
- Each bundle marked with heat number, steel grade Q235B/Q345, size, and bundle weight for on-site identification
- Shipping terms FOB, CIF, and DDP available with professional export documentation handling
Ready to Lock in Pricing and Certification
Submit your size, wall thickness, steel grade, quantity, and destination port — we return a detailed quotation with mill test certificate confirmation and estimated production schedule within 12 hours. For non-standard dimensions or custom zinc coating requirements, share your drawing and we provide a feasibility assessment with tooling timeline.
Request Your Galvanized Square Steel Tube Quote Today
Send specifications via email or WhatsApp to receive factory-direct pricing and full documentation support.
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@sdxinjiyuan.com
Frequently Asked Questions
Q: What is the difference between Q235 and Q345 for galvanized square steel tubes?
A: Q345 offers higher yield strength than Q235, making it suitable for heavier structural loads. Both grades are fully weldable and can be hot-dip galvanized. The choice depends on your structural design calculations and load requirements.
Q: Can you provide EN 10219 certified galvanized square tubes for European projects?
A: Yes. Our production is CE certified under EN 10210 and EN 10219, and we supply cold-formed welded hollow sections meeting these standards. Mill test certificates and third-party inspection reports are provided with every shipment.
Q: What zinc coating weight do you offer for galvanized square steel tubes?
A: We provide hot-dip galvanized coating in the range of 30–275g/m². For indoor or dry environments, lighter coatings are cost-effective. For outdoor, industrial, or coastal exposure, we recommend higher coating weights for extended corrosion protection.
Q: What is the minimum order quantity for custom non-standard sizes?
A: Our flexible MOQ starts from 1 ton. Standard sizes ship from ready stock. Custom non-standard dimensions and special lengths are produced on our ERW lines within typical production lead times.
Q: Do you handle container loading optimization for mixed-size orders?
A: Yes. Our export team prepares detailed container loading plans to maximize payload and minimize freight cost per ton. We support consolidated loading of multiple steel product categories in a single container.
