Description
Factory-direct pricing, no trading markup — XJY Structure operates its own steel mill and fabrication line, delivering Q235, S235, and SS400 galvanized square steel tubes with full material traceability from raw coil to finished bundle.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235 / S235 / SS400 Galvanized Square Steel Tube |
| Product Type | Galvanized Square and Rectangular Steel Tube (SHS / RHS) |
| Steel Grade | Q195, Q215, Q235, Q345, S235, SS400 |
| Standard | GB |
| Section Shape | Square, Rectangular, Round |
| Wall Thickness | 0.5–80 mm |
| Length | 6 m (standard), customizable |
| Technique | ERW (Electric Resistance Welded) |
| Surface Treatment | Galvanized (Hot-dip / Electro-galvanized), Zn coating 30–650 g/m² |
| Tolerance | ±1% |
| Ends | Non-oiled |
| Application | Steel structures, Construction frames, Scaffolding, Machinery, Furniture, Bridge, Electrical installation, Mining |
| MOQ | 25 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| EPC & General Contractors | Industrial warehouse frames, logistics center columns, plant support structures |
| Construction & Scaffolding | Scaffold systems, temporary works platforms, site access structures |
| Machinery & Equipment | Machine frames, conveyor supports, hydraulic mounting structures |
| Electrical & Infrastructure | Cable tray supports, substation frameworks, bridge handrails |
What Zinc Coating Weight Decides on a Scaffolding Order
Coating thickness is the single most contested item at site acceptance — and the easiest to fake on paper.
I spent three months supervising steel installation on a warehouse project in Riyadh. The galvanized scaffolding tubes arrived with zinc coating measured at 35 microns. The contract specified 65 microns minimum. The consultant pulled out his coating thickness gauge on the first day, rejected the entire batch, and sent it to the laydown yard. Two weeks of delay followed before replacement material cleared customs. [NEED_CITE: hot-dip galvanized coating thickness requirements for structural steel in corrosive environments]
When you source galvanized square steel tube from fragmented suppliers who buy black tubes from one mill and send them to a separate galvanizing shop, you lose control over coating uniformity, adhesion, and documentation. Our vertically integrated operation — own steel production, own ERW forming line, own galvanizing bath — means every batch carries a single quality chain from coil to shipment. The Zn coating range of 30–650 g/m² covers everything from indoor furniture frames to heavy industrial exposure, and every heat number traces back to our mill test records.
Matching Wall Thickness to Structural Load Paths
For scaffolding and light structural frames, the 0.5–80 mm wall thickness range of this galvanized square steel tube covers both non-load-bearing cladding supports and primary column members. The ±1% tolerance means what you specify on the drawing is what arrives on site — critical when connection plates are pre-drilled to match tube dimensions. ERW welding produces a consistent longitudinal seam that maintains dimensional accuracy across square and rectangular profiles, avoiding the ovality issues common in lower-cost forming processes.
Compliance Requirements Across Project Regions
Structural applications in the Middle East and Southeast Asia typically require GB-compliant material with third-party inspection reports. The Q235 and S235 grades in this product line meet the yield strength requirements for general construction frames, while Q345 serves heavier load conditions. [NEED_CITE: steel grade equivalence between GB and international standards for structural hollow sections] For projects requiring CE marking or EN 1090 execution class documentation, our engineering team provides shop drawing review and fabrication sequencing support to ensure the galvanized square steel tube integrates with certified connection details.
Understanding ERW Process and Galvanizing Options
The ERW (Electric Resistance Welded) process used for these square and rectangular tubes creates a high-frequency weld seam that is subsequently normalized, producing a weld zone with mechanical properties matching the parent material. This matters for galvanized square steel tube because the zinc coating adheres uniformly across both the base metal and the weld seam — unlike some lower-quality ERW where weld flash or inclusions cause coating blistering. Hot-dip galvanizing at 30–650 g/m² provides sacrificial corrosion protection suitable for outdoor exposure, while electro-galvanized finishes serve indoor applications where appearance matters more than corrosion resistance. The non-oiled surface condition means these tubes are welding-ready upon arrival — no solvent cleaning required before MIG or TIG connections.
The Hidden Cost of Unverified Coating Claims
Ordering galvanized square steel tube based on price alone, without requiring third-party coating thickness verification, creates three failure modes at project sites. First, underspecified zinc coating fails visual inspection and thickness testing, triggering full-batch rejection and replacement delays. Second, inconsistent coating adhesion causes premature flaking during handling and installation, exposing bare steel to corrosion before the structure is even commissioned. Third, missing material traceability documentation blocks customs clearance in markets requiring certified mill test reports. [NEED_CITE: consequences of non-compliant galvanized coatings in structural steel procurement] These costs — measured in demurrage charges, re-fabrication labor, and schedule penalties — routinely exceed the price difference between verified and unverified suppliers.
Why Project Teams Specify XJY Structure
Our vertically integrated operation eliminates the material sourcing gap that creates quality uncertainty. We produce our own steel coil, form it through ERW into square and rectangular profiles, and galvanize in-house — meaning one quality system covers the entire process. Every galvanized square steel tube shipment includes mill test certificates with chemical composition and mechanical properties tied to specific heat numbers. Our facility holds ISO 9001 certification, and we arrange SGS or BV third-party inspection for coating thickness, dimensional verification, and surface quality before loading. The 2,800+ specification range in our inventory means standard sizes ship within typical production lead times, while custom lengths and non-standard dimensions are fabricated to order. Professional export packing with edge protectors preserves the zinc coating during ocean transit, and our logistics team handles oversized cargo loading for containers optimized to 25-ton payloads.
Documentation & Compliance
- Mill test certificate documenting Q235/S235/SS400 chemical composition and mechanical properties per GB standard, with heat number traceability
- Third-party inspection report (SGS/BV) verifying zinc coating thickness within 30–650 g/m² range and dimensional tolerance of ±1%
- ISO 9001 quality management system certificate covering steel production and galvanizing processes
- Material traceability report linking each bundle to specific heat numbers and production dates
- Export documentation package including packing list, bill of lading, and certificate of origin for customs clearance
Packaging, Loading & Delivery
- Galvanized square and rectangular tubes bundled with steel straps and edge protectors to prevent zinc coating damage during handling and transit
- Non-oiled surface condition allows immediate welding upon arrival, with protective wrapping available for high-humidity ocean routes
- Standard 6 m length optimized for 20ft container loading at 25-ton MOQ, with custom cut lengths available for specific project requirements
- Heat number and steel grade markings stenciled on each bundle for site identification and inspection verification
- FOB, CIF, and DDP shipping terms available, with door-to-door logistics coordination for project sites in the Middle East, Southeast Asia, and Africa
Getting Your Quote and Material Verification
Submit your project specifications — including steel grade (Q235, S235, SS400), section dimensions, wall thickness, coating weight requirement, and total tonnage — to receive a detailed quotation with production schedule and mill test certificate samples. For non-standard dimensions or custom lengths, our engineering team reviews your drawings and provides fabrication feasibility confirmation. We confirm third-party inspection availability, certification requirements for your destination market, and container loading optimization before contract signing.
Frequently Asked Questions
Q: What is the difference between hot-dip and electro-galvanized coating for square steel tubes?
A: Hot-dip galvanizing produces a thicker zinc coating (typically 65–650 g/m²) with superior corrosion resistance for outdoor and industrial environments. Electro-galvanizing provides a thinner, more uniform coating (30–60 g/m²) suitable for indoor applications where appearance and formability matter more than long-term corrosion protection.
Q: How do you handle theoretical weight versus actual weight for invoicing?
A: All galvanized square steel tubes are invoiced by theoretical weight calculated from specified dimensions and wall thickness, with ±1% tolerance. This eliminates weight variation disputes and provides transparent costing based on engineering drawings rather than scale weight.
Q: What is the minimum order quantity and container loading capacity?
A: The MOQ is 25 tons per order. Standard 6 m lengths are optimized for 20ft container loading, with bundle configurations designed to maximize payload while protecting the galvanized coating during transit.
Q: Can you provide custom lengths and special packing for overseas shipment?
A: Yes, custom cut lengths are available beyond the standard 6 m. Export-standard packing includes steel strap bundling, edge protectors for coating preservation, and moisture-resistant wrapping for high-humidity shipping routes.
Q: What is the typical production lead time for standard versus custom sizes?
A: Standard sizes from our 2,800+ specification inventory ship within typical production lead times. Custom dimensions and non-standard coating weights require additional forming and galvanizing scheduling, with specific timelines confirmed during quotation.
Request Your Galvanized Square Steel Tube Quotation
Send your project drawings, steel grade requirements, and coating specifications to receive pricing with full mill test certificate documentation and third-party inspection confirmation.
Contact: Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.xjystructure.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@xjystructure.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
