Description
Factory-Direct Galvanized SHS/RHS — Q235 rectangular and square hollow sections produced on our own ERW lines, shipped without trading margins.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235 Galvanized Square and Rectangular Steel Tube |
| Product Type | Galvanized Square / Rectangular Steel Tube (SHS/RHS) |
| Steel Grade | Q195, Q215, Q235, Q345, 10#, 20#, 45#, 16Mn, ASTM A53 (Grade A/B), St37, St42, St35.4, St52.4, Grade 50 |
| Standard | BS EN, GB, AISI, ASTM, DIN, JIS |
| Section Shape | Square / Rectangular / Round |
| Size Range | 10 mm – 1000 mm |
| Wall Thickness | 0.6 mm – 28 mm |
| Length | 1 m – 12 m |
| Technique | Hot Rolled / Cold Rolled / ERW |
| Surface Treatment | Galvanized (Zinc Coating 30–275 g/m²), Bare, Oiled, Color Painted, 3PE |
| Ends | Plain, Beveled, Threaded with Couplings/Sockets |
| Application | Steel structures, construction frames, fencing, cars, bridges, ships, boilers, pressure vessels, general engineering structures, machinery manufacturing |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| EPC Contractors & Construction | Structural frames, scaffolding, fencing, building skeletons for infrastructure projects |
| Machinery Manufacturers | Equipment frames, conveyor structures, precision galvanized supports |
| Industrial Distributors | Regional stock of square, rectangular, and round sections for resale |
| Bridge & Ship Builders | Load-bearing hollow sections, deck supports, marine structure frames |
Where Zinc Coating Weight Decides Project Acceptance
A 42 μm coating passing as 80 μm will fail SGS inspection at the destination port — and the container sits there for weeks while your project waits.
I have seen this happen on the Jebel Ali dock. A contractor ordered 100×50×3 mm galvanized rectangular tubes, and the zinc layer came in well below the specified 80 μm. The entire shipment was rejected, the project timeline slipped, and the replacement cost wiped out any savings from choosing a cheaper supplier. That is why, as a Galvanized Square and Rectangular Steel Tube Manufacturer, we run every coating report through our in-house physical and chemical laboratory before anything gets loaded. Quality uncertainty on zinc thickness, unclear steel grade traceability, and missing mill test certificates remain the top reasons shipments get held up at customs or rejected on site [NEED_CITE: EN 10219 cold-formed hollow section requirements].
Matching Wall Thickness and Zinc Weight to Corrosive Environments
Galvanized SHS and RHS are specified for environments where bare steel would corrode within a few years — outdoor structural frames, coastal scaffolding, industrial fencing, and machinery exposed to humidity. The zinc coating range of 30–275 g/m² lets engineers balance cost against service life: lighter coatings suit indoor or temporary structures, while heavier coatings protect bridges, ships, and outdoor frames for decades. As a Galvanized Square and Rectangular Steel Tube Manufacturer, we produce sections from 10 mm up to 1000 mm with wall thickness up to 28 mm, covering everything from light-duty conveyor frames to heavy-load building columns. Custom non-standard sizes are available for projects where standard catalog dimensions do not fit the design.
Structural Code Compliance and Certification Path
For EU-bound projects, the tubes must conform to EN 10219 for cold-formed welded structural hollow sections, and CE certification under EN 10210 / EN 10219 is required for customs clearance [NEED_CITE: EN 10219 cold-formed hollow section requirements]. North American buyers typically specify ASTM A53 or ASTM A500, while GB-standard Q235 and Q345 dominate domestic Chinese and many Belt & Road projects. Our mill holds CE, ISO 9001:2015, Singapore FPC, and third-party verification from SGS and BV, so the documentation package matches the destination market. Engineers designing to EN 1993 or AISC can rely on the sectional properties and tolerance ranges defined in EN 10219-2 [NEED_CITE: EN 10219-2 tolerance dimensions sectional properties].
Steel Grade Selection and Forming Process
Q235 remains the workhorse grade for general structural frames in China and many export markets — it offers adequate yield strength for building skeletons, fencing, and scaffolding at a competitive price point. When higher load capacity is needed, Q345 or Grade 50 steps in. For projects specifying international standards, ASTM A53 Grade A/B and St37/St52 cover European and American requirements. The ERW forming process produces a longitudinal weld seam that is suitable for structural hollow sections up to moderate wall thicknesses, while hot-rolled and cold-rolled options address different surface finish and dimensional accuracy needs. Our proprietary sharp-corner rectangular tube technology fills a gap that standard ERW dies cannot achieve — the corners on a sharp-corner RHS sit flush against mating plates, which improves load transfer and gives a cleaner appearance on exposed architectural frames [NEED_CITE: steel grade equivalence between EN and ASTM standards].
The Hidden Cost of Wrong-Grade Procurement
Ordering Q195 when the structural drawing calls for Q235 may save a few dollars per ton on paper, but it means lower yield strength, potential failure during load testing, and rejection by the project engineer. Missing or incomplete CE certificates cause customs delays in the EU — a container held at Rotterdam or Hamburg adds demurrage, storage fees, and weeks of schedule slippage. Negative tolerance beyond the allowable range means the actual weight falls short of the theoretical calculation, so the buyer pays for steel that is not there. These are not theoretical risks; they are the most common reasons EPC contractors switch suppliers mid-project [NEED_CITE: EN 10219 cold-formed hollow section requirements].
Why Buyers Choose Xin Jiyuan as Their Galvanized SHS/RHS Source
We run three dedicated production lines with in-house physical and chemical laboratories, so every heat of steel is tested before it reaches the forming line and every batch is checked again before shipment. Our mill holds 41 invention patents, including the sharp-corner rectangular tube technology that lets us produce RHS with tight corner radii that standard dies cannot achieve. The product catalog covers over 2,800 specifications with wall thickness up to 40 mm, and custom non-standard sizes are available for projects that fall outside the standard range. CE certification under EN 10210 / EN 10219, ISO 9001:2015, Singapore FPC, and SGS/BV third-party inspection reports travel with every shipment. We export to 50+ countries across the EU, North America, India, Southeast Asia, and the Middle East, with professional loading plans that optimize container space for mixed-size orders.
Documentation & Compliance
- Mill test certificate documenting Q235 chemical composition and mechanical properties per GB/T 700, with heat number traceability
- CE certificate under EN 10210 / EN 10219 for EU market customs clearance and project compliance
- ISO 9001:2015 quality management system certificate covering the full production process
- SGS or BV third-party inspection report verifying zinc coating weight and dimensional tolerance before shipment
- Material traceability by heat number linking each tube back to the original steel coil test data
- Full customs document package including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- Galvanized tubes bundled with steel strips and edge protectors to preserve the zinc coating during ocean transit
- Surface protection maintained through plastic caps on tube ends and anti-rust wrapping for bare or oiled sections
- Container loading optimized for mixed-size orders — 10 mm to 1000 mm sections nested to maximize 20 ft and 40 ft container space
- Custom cutting to 1 m – 12 m lengths available, with saw-cut ends deburred and capped
- Heat number and steel grade stenciled on each bundle for site identification and traceability
- FOB, CIF, and DDP terms available with door-to-door logistics coordination to 50+ countries
Start Your Procurement with Full Documentation
Submit your specifications — section size, wall thickness, steel grade, zinc coating weight, quantity, and destination port — and receive a detailed quotation with delivery timeline and applicable certification within 12 hours. We will confirm the mill test certificate format, third-party inspection arrangement, and container loading plan before production begins.
Request a Quote with Mill Test Certificate
Send your requirements via email to admin@sdxjysteel.com or contact us on WhatsApp at +86 188 5315 7756.
Frequently Asked Questions
Q: What is the difference between Q235, S235JR, and ASTM A36 — which should I specify?
A: Q235 is the Chinese GB standard grade, S235JR is the European EN equivalent, and ASTM A36 is the American counterpart. All three share similar yield strength ranges and are used for general structural applications. We produce to all three standards and can supply the corresponding mill test certificate for your market.
Q: How do I choose between galvanized, hot-rolled bare, and 3PE surface treatment?
A: Galvanized coating at 30–275 g/m² suits outdoor and corrosive environments — fencing, scaffolding, coastal structures. Bare or oiled sections work for indoor applications or where the steel will be painted on site. 3PE coating is typically specified for buried pipelines requiring higher corrosion protection. We can advise based on your project environment.
Q: Can you produce non-standard sizes to my drawing?
A: Yes. Our three production lines cover over 2,800 standard specifications, and we manufacture custom non-standard sizes for square, rectangular, and round sections. MOQ for custom sizes is 1 Ton. Send your drawing or specification sheet and we will confirm feasibility and lead time.
Q: What certification do I need for EU customs clearance?
A: EU-bound structural hollow sections require CE certification under EN 10210 or EN 10219, along with a mill test certificate and declaration of performance. Our mill holds CE certification for these standards, and the full document package travels with every shipment.
Q: How is pricing calculated — theoretical weight or actual weight?
A: Pricing is based on theoretical weight calculated from the specified dimensions and wall thickness, following the standard formula for the relevant section shape. Negative tolerance is controlled within the limits defined by EN 10219-2 or the applicable standard. We confirm the tolerance range before production.
Get Factory-Direct Pricing with Full Traceability
Email your specifications to admin@sdxjysteel.com or WhatsApp +86 188 5315 7756 for a quotation including mill test certificate and delivery schedule.
