Description
Factory-direct mill supply — Every 40×40 mm galvanized square steel tube rolls from our own billet line, so heat numbers trace straight back to the ladle without a middleman’s paperwork.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Galvanized Square Steel Tube |
| Product Type | Square Steel Tube (SHS) |
| Steel Grade | Q195, Q215, Q235, Q345, GR.A, GR.B, S235, S355 |
| Standard | ASTM A213, DIN EN 10217-1 |
| Section Shape | Square |
| Side Length | 40 × 40 mm |
| Wall Thickness | 1 mm |
| Length | 12 m |
| Technique | ERW (Welded) |
| Surface Treatment | Pre-galvanized / Hot dipped galvanized / Bare / Oil-free |
| Tolerance | ±1% |
| Ends | Plain |
| Application | Steel structures, Steel fences, Steel posts, Warehouse construction, Building construction |
| MOQ | 10 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Warehouse & Logistics Construction | Portal frame purlins, mezzanine support posts, racking uprights |
| Agricultural & Industrial Fencing | Perimeter fence posts, gate frames, livestock pen structures |
| Commercial Building Construction | Curtain wall sub-frames, canopy supports, non-load-bearing columns |
| Infrastructure & Civil Works | Highway signpost bases, lighting pole foundations, cable tray supports |
What Coating Consistency Costs When a Third-Party Inspector Shows Up on Site
A 45-micron zinc reading against an 80-micron spec means the whole lot gets rejected — and air-freighting replacements eats your margin.
Outsourcing galvanized square steel tube procurement overseas introduces a quality-distance gap that no brochure can close. Buyers routinely discover coating thickness shortfalls, inconsistent passivation, or missing heat-number traceability only when the material reaches the job site. [NEED_CITE: hot-dip galvanized coating thickness standards per ISO 1461] The problem compounds when the fabricator sources raw tubes from a third mill — the certification chain breaks, and re-inspection becomes a gamble. With a vertically integrated mill supplying the galvanized square steel tube directly, the same quality system that produced the billet verifies the coating, and every heat number on the tube matches the mill test certificate in your hand.
How 40×40 mm SHS Meets Structural Framing and Fence Post Demands
The 40 × 40 mm square section delivers a balanced moment of inertia for light-to-medium structural frames, while the 1 mm wall keeps weight manageable for manual handling on fence and post installations. Pre-galvanized or hot-dipped galvanized surface treatment resists atmospheric corrosion in outdoor environments — critical for perimeter fencing and warehouse cladding supports where touch-up painting is impractical. The ±1% tolerance on side length ensures that connection plates and base brackets fit without on-site grinding, which matters when a galvanized square steel tube order runs into hundreds of pieces across a single project.
Engineering Compliance and Certification Pathways
Structural frames designed to EN 1993 or AISC 360 require documented material properties, and customs authorities in the EU increasingly request CE marking evidence for load-bearing hollow sections. [NEED_CITE: EN 10219 cold-formed structural hollow sections certification requirements] Specifying S235 or S355 grade steel aligns with European design codes, while Q235 and Q345 serve projects following Chinese or GB-based specifications. The 12 m standard length reduces on-site welding joints, but site-specific cutting must preserve the galvanized coating at cut edges — a detail that separates a compliant installation from a corrosion failure two years later.
Steel Grade Selection and ERW Weld Integrity
The Q-series (Q195–Q345) and S-series (S235–S355) represent Chinese and European yield strength classification systems respectively; Q235 roughly corresponds to S235 in minimum yield behavior, while Q345 parallels S355. For a galvanized square steel tube in fence post or non-primary structural use, Q195 or Q215 offers adequate strength at lower cost. ERW welding produces a longitudinal seam that, when properly normalized and inspected, performs reliably in square sections up to moderate wall thicknesses. [NEED_CITE: ERW weld seam quality requirements for structural hollow sections] The 1 mm wall on a 40 mm section creates a slender profile where sharp, well-formed corners matter for both aesthetic alignment and gusset plate contact.
Hidden Costs of Getting the Grade or Coating Wrong
Substituting a lower steel grade without engineer approval can trigger structural review delays and potential re-fabrication if load calculations no longer hold. Coating thickness that falls below specification — whether from inadequate bath time or poor surface preparation — accelerates corrosion at weld zones and cut edges, leading to premature maintenance or replacement. [NEED_CITE: galvanized coating adhesion and thickness inspection methods] Missing or mismatched mill test certificates create customs clearance bottlenecks, particularly in markets requiring EN 10210 or ASTM A500 compliance documentation.
Why Sourcing from an Integrated Mill Changes the Risk Profile
Our own steel mill produces the billet, rolls the tube, and applies the galvanizing — meaning one facility controls chemistry, dimensions, and coating from start to finish. The mill test certificate you receive carries a heat number that traces to our ladle log, not a purchased tube from an unknown supplier. We maintain 2,800+ specifications in stock, so a 10-ton order of 40×40×1 mm galvanized square steel tube ships from existing inventory rather than waiting for raw material procurement. CE certification under EN 10210/EN 10219, ISO 9001 quality management, and third-party inspection through SGS or BV are standard offerings — not special requests. Professional loading plans maximize container utilization for 12 m lengths, and export documentation follows your destination port’s requirements.
Documentation & Compliance
- Mill test certificate documenting Q235 or S355 chemical composition and mechanical properties per DIN EN 10217-1, with heat number traceability to our steel mill
- CE certificate confirming compliance with EN 10210 (hot-finished) or EN 10219 (cold-formed) structural hollow section standards for European market access
- ISO 9001 quality management system certificate covering the full production chain from billet to galvanized finished tube
- SGS or BV third-party inspection report verifying coating thickness, dimensional tolerance, and weld quality prior to shipment
- Material traceability sheet linking each bundle’s heat number to production date, steel grade, and coating batch
- Complete customs documentation package including packing list, bill of lading, and certificate of origin formatted for destination country requirements
Packaging, Loading & Delivery
- Galvanized square steel tubes bundled with high-tensile steel strips and edge protectors to preserve the zinc coating and prevent bundle distortion during ocean transit
- 12 m standard length loaded in 20ft or 40ft containers using optimized stowage plans that maximize weight utilization while protecting tube ends from impact damage
- Surface protection maintained through oil-free galvanizing or passivation treatment, with plastic end caps on plain ends to prevent moisture ingress and edge corrosion
- Heat number and steel grade stenciled on each bundle tag, with color-coding by grade (Q235/S235 vs Q345/S355) for rapid site identification
- FOB Jinan or Qingdao port pricing available, with CIF and DDP options to major construction markets in the Middle East, Southeast Asia, and Africa
- Custom cutting to non-standard lengths available upon request, with minimum order quantities adjusted for non-stock sizes
Ready to Lock in Mill-Direct Pricing and Full Traceability?
Send your specification sheet — including steel grade, surface treatment preference, quantity, and destination port — and receive a detailed quotation with production timeline and mill test certificate sample within 24 hours. Our engineering team reviews shop drawings for material optimization and confirms coating thickness compliance before the first tube rolls.
Request Your Quotation and Mill Test Certificate
Submit your project specifications to admin@xjystructure.com or contact us via WhatsApp at +86 188 5315 7756 for pricing, certification details, and delivery scheduling.
Frequently Asked Questions
Q: What is the difference between Q235 and S235 steel grade for this galvanized square steel tube?
A: Q235 (Chinese GB standard) and S235 (European EN standard) have similar minimum yield strength characteristics and are often considered equivalent for general structural applications. The choice depends on your project’s design code requirements and local inspection authority preferences. Both grades are available in our 40×40 mm galvanized square steel tube range.
Q: Can you provide third-party inspection for coating thickness and dimensional tolerance?
A: Yes, we coordinate SGS or BV third-party inspection at our facility before shipment. The inspection covers zinc coating thickness measurement, dimensional verification against ±1% tolerance, and visual weld quality assessment. Inspection reports are included in the shipping documentation package.
Q: What galvanized coating thickness options are available?
A: We offer pre-galvanized (typically 40-80 microns) and hot-dipped galvanized (typically 60-120 microns depending on steel grade and immersion time) options. Specific coating thickness requirements should be stated in your inquiry, and we confirm compliance capability before order placement. Oil-free galvanizing is available for projects requiring subsequent painting or powder coating.
Q: What is the minimum order quantity for custom lengths or non-standard sizes?
A: Standard 12 m length galvanized square steel tubes in 40×40×1 mm have a 10-ton MOQ. Custom cutting to non-standard lengths or non-stock size combinations may require higher MOQ depending on mill scheduling. Contact us with your specific requirements for a tailored quotation.
Q: Do you provide CE certification for European projects?
A: Yes, our galvanized square steel tubes can be supplied with CE marking under EN 10210 (hot-finished structural hollow sections) or EN 10219 (cold-formed structural hollow sections) as applicable. CE documentation includes Declaration of Performance and factory production control certificates required for EU market access.
Get Factory-Direct Pricing with Full Mill Documentation
Email your specification sheet to admin@xjystructure.com or WhatsApp +86 188 5315 7756 to receive a quotation with mill test certificate sample within 24 hours.
