Description
Factory-direct galvanized SHS/RHS — Vertically integrated from raw steel production to finished Q235B square and rectangular tubes with full mill traceability.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235B Galvanized Square and Rectangular Steel Tube |
| Product Type | Galvanized Square and Rectangular Steel Tube (SHS/RHS) |
| Steel Grade | Q195, Q215, Q235, Q345 |
| Standard | BS, EN, GB, AISI, ASTM, DIN, JIS |
| Section Shape | Square / Rectangular |
| Size Range | 10mm–1000mm |
| Wall Thickness | 0.6–28mm |
| Length | 1–12m (or customized) |
| Technique | ERW (Hot Rolled / Cold Rolled) |
| Surface Treatment | Galvanized (Zinc Coating: 30–275g/m²) |
| Tolerance | ±1% |
| Ends | Plain / Beveled / Threaded with couplings or sockets |
| Application | Steel structures, building frames, general engineering, bridges, ships, boilers, pressure vessels |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Architecture | Building frames, column supports, roof trusses, curtain wall sub-structures |
| Infrastructure | Bridge handrails, highway sign gantries, sound barrier posts |
| Industrial & Manufacturing | Conveyor frames, machinery bases, equipment support platforms |
| Energy & Utilities | Solar panel mounting structures, substation support frames |
| Marine & Shipbuilding | Deck railings, ventilation ducts, non-pressure piping runs |
What Zinc Coating Thickness Actually Means for Your Project Timeline
A 30g/m² coating and a 275g/m² coating behave completely differently once the tubes reach your job site.
Overseas buyers sourcing a Galvanized Square and Rectangular Steel Tube Supplier often discover the zinc specification mismatch only after arrival — when welders struggle with spatter on thin coatings, or when exposed edges begin white rust within weeks in humid coastal climates. The gap between pre-shipment samples and bulk production zinc thickness is one of the most common root causes of field rework on structural projects. [NEED_CITE: hot-dip galvanized coating thickness standards for structural steel]
Matching Wall Thickness Tolerance to Structural Connection Requirements
When Q235B galvanized tubes arrive at a steel frame assembly yard with wall thickness varying beyond ±1%, bolted connections on moment frames fail to seat properly, and weld prep gaps exceed allowable limits. The Galvanized Square and Rectangular Steel Tube we produce maintains ±1% tolerance across the full 0.6–28mm range, which means site crews spend less time shimming and re-fitting. Our vertically integrated mill controls both the ERW forming and the galvanizing line, so dimensional consistency carries through from raw coil to finished bundle.
Engineering Compliance Across International Standards Frameworks
Structural engineers specifying galvanized SHS/RHS for load-bearing frames need documentation that satisfies both the design code and the importing country’s customs requirements. Q235B maps closely to S235JR under EN 10219 and A36 under ASTM A53, but the equivalence must be backed by proper mill test certificates and third-party inspection reports — not assumed from the grade number alone. [NEED_CITE: steel grade equivalence between GB Q-series and EN S-series standards] For projects entering the EU market, EN 10219 compliance with CE marking becomes mandatory, while Middle Eastern and Southeast Asian buyers typically require ASTM or JIS conformance with SGS or BV verification.
Understanding Q-Series Steel Grades and ERW Process Selection
The Q in Q235B denotes yield point in MPa under the Chinese GB standard system, where Q195, Q215, Q235, and Q345 represent ascending yield strength levels suited to progressively heavier structural demands. Q195 and Q215 serve light-duty applications such as furniture frames and fence posts, while Q235B — the most widely specified grade — handles general building frames, equipment supports, and infrastructure components. Q345 steps into heavier bridge and industrial plant structures where higher load capacity is required. Our ERW process offers both hot-rolled and cold-rolled options: hot-rolled strips suit thicker walls above 3mm where forming force is higher, while cold-rolled strips deliver tighter surface finish and dimensional precision for thinner-walled tubes down to 0.6mm. The galvanized coating at 30–275g/m² provides corrosion protection proportional to the service environment — indoor dry conditions need minimal zinc, while outdoor industrial or coastal exposure demands the upper range.
The Hidden Cost of Unverified Material on Structural Projects
Accepting a Galvanized Square and Rectangular Steel Tube Supplier without verified mill test certificates creates a cascade of downstream risks: customs authorities in destination countries increasingly reject shipments lacking proper chemical composition documentation, and site inspectors flagging material without heat-number traceability can halt an entire erection sequence. [NEED_CITE: customs documentation requirements for imported structural steel tubes] The real cost is never the per-ton price difference — it is the crane idle time, the re-inspection fees, and the contractual penalties when project handover dates slip.
Procurement Confidence Through Vertical Integration
Our production model eliminates the material sourcing gap that causes most quality disputes. We operate our own steel mill with three production lines and maintain over 2,800 raw material specifications in inventory, meaning every galvanized tube we ship carries full traceability from steelmaking heat number through ERW welding to the galvanizing bath. Certified welding procedures and qualified welders under AWS and EN standards ensure that any fabrication or modification work meets international code requirements. Our engineering team reviews shop drawings before production begins, catching dimension conflicts and connection detail issues while corrections still cost nothing. Professional container loading plans — developed from years of shipping oversized SHS/RHS to Latin America, the Middle East, and Southeast Asia — prevent the transit deformation that destroys galvanized coatings and bends thin-walled sections.
Documentation & Compliance
- Mill test certificate documenting Q235B chemical composition and mechanical properties per GB/T 6728, with heat number traceability for every bundle
- CE certificate under EN 10219 for cold-formed structural hollow sections, required for projects entering European Union markets
- ISO 9001 quality management system certificate covering the full production chain from raw steel to galvanized finished product
- SGS or BV third-party inspection report verifying zinc coating thickness, dimensional tolerance, and surface quality before shipment
- Complete customs documentation package including packing list, bill of lading, and certificate of origin formatted for destination port requirements
Packaging, Loading & Delivery
- Q235B galvanized tubes bundled with steel strips and edge protectors to preserve the zinc coating from abrasion during ocean transit
- Seaworthy packaging with waterproof wrapping for containers, suitable for 1–12m lengths loaded in 20ft and 40ft containers with optimized nesting for square and rectangular profiles
- Galvanized surface protected by passivation treatment to prevent white rust formation during extended shipping to humid destination ports
- Heat number and steel grade stenciled on each bundle for on-site identification and traceability verification
- Custom cutting to project-specific lengths available, reducing on-site waste and welding joints for structural frame assembly
- FOB, CIF, and DDP terms supported with professional loading plans for oversized cargo and complete export documentation
Starting Your Procurement Process
Share your project drawings in PDF or DWG format along with the required steel grade, section dimensions, wall thickness, zinc coating specification, and destination port. Our engineering team responds within 24 hours with a preliminary assessment, followed by a detailed quotation covering material, fabrication, coating, packing, and shipping costs with a shop drawing timeline and production schedule included.
Request Your Galvanized SHS/RHS Quotation
Submit your specifications and steel grade requirements to receive pricing, mill test certificate samples, and a production timeline.
Company: 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
