Description
Factory-Direct Galvanized Square & Rectangular Steel Tube Supplier — We manufacture and ship Q235, S355, and ASTM A500 grade galvanized square and rectangular steel tubes directly from our Jinan production facility to 50+ countries, eliminating trading margins.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Galvanized Square and Rectangular Steel Tube |
| Product Type | Square / Rectangular / Round hollow sections |
| Steel Grade | Q195, Q215, Q235, Q345, S235, S355, ASTM A500 Grade B/C/D, ASTM A53 Grade A/B, 10#, 20#, 45#, 16Mn, St37, St42, St35.4, St52.4 |
| Standard | BS EN, GB, AISI, ASTM, DIN, JIS, ISO 9001 |
| Section Shape | Square / Rectangular / Round |
| Size Range | Side length / Outer Diameter: 10 mm – 1000 mm |
| Wall Thickness | 0.6 – 28 mm |
| Length | 1 – 12 m (or customized) |
| Technique | ERW (Hot Rolled / Cold Rolled) |
| Surface Treatment | Galvanized (30–275 g/m²), Bare, Oiled, Color Paint, 3PE, PVC |
| Zinc Coating | 30 – 275 g/m² |
| Ends | Plain, Beveled, Threaded with Couplings or Sockets |
| Application | Steel structures / Construction frames / Fencing / Machinery / Bridges / Ships / Boilers / Pressure vessels / General engineering structures |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| EPC Contractors & Construction | Building frames, scaffolding systems, fencing structures, infrastructure supports |
| Machinery Manufacturers | Equipment frames, conveyor structures, hydraulic cylinder housings |
| Industrial & Agricultural | Greenhouse frames, solar panel mounting structures, warehouse racking systems |
| Bridge & Ship Engineering | Structural bracing, deck supports, pressure vessel shells |
Where EN 10219 Certification Decides Customs Clearance for Galvanized Square and Rectangular Steel Tube
A missing or mismatched EN 10219 certificate can hold an entire container at EU customs for weeks.
I have seen EPC procurement teams discover too late that their supplier’s mill test certificate references EN 10210 (hot-finished) instead of EN 10219 (cold-formed welded), triggering a full document rejection at the port of entry. The galvanized square and rectangular steel tube arrives on schedule, but the paperwork does not match the cold-formed ERW production method declared on the commercial invoice. Customs officers in Rotterdam, Lagos, or Dubai will not release the cargo until the conformity gap is closed — and that usually means flying in a replacement certificate or paying for a third-party re-inspection at the destination. [NEED_CITE: EN 10219 cold-formed welded hollow section technical delivery conditions]
Beyond customs, the structural engineer reviewing your submission package will cross-check the steel grade designation against EN 10219-2 requirements for cold-formed sections. If the certificate lists a hot-rolled grade without the appropriate J2H or JRH suffix for low-temperature impact testing, the entire batch may fail the design compliance review — regardless of whether the physical tubes are perfectly sound.
How Galvanized Square and Rectangular Steel Tube Matches Structural Frame Requirements
When an EPC contractor specifies galvanized square and rectangular steel tube for a building frame or scaffolding system, the primary concerns are load-bearing capacity, corrosion resistance in exposed environments, and dimensional accuracy at connection points. The ERW cold-forming process produces tight corner radii and consistent wall thickness, which matters when bolted or welded connections must align precisely on-site. The galvanized zinc coating (30–275 g/m²) provides sacrificial protection against atmospheric corrosion, extending service life in outdoor or humid industrial environments without requiring field painting. Our production lines cover side lengths from 10 mm to 1000 mm and wall thicknesses up to 28 mm, meaning a single supplier can deliver the full range of structural sections — from small fencing posts to large bracing members — in one shipment.
Engineering Compliance and Certification Requirements for Cold-Formed Hollow Sections
Structural design codes such as EN 1993-1-1 (Eurocode 3) and AISC 360 reference specific material standards for cold-formed welded hollow sections. EN 10219 covers non-alloy and fine-grain structural steels in cold-formed welded square, rectangular, and circular sections, while ASTM A500 serves the North American market. The steel grade selection — S235JR for general structures, S355J2H for low-temperature or dynamic loading — directly affects the design strength values available to the engineer. Certification requirements vary by destination: EU projects typically require CE marking under EN 10210/EN 10219, while Southeast Asian infrastructure contracts may specify Singapore FPC certification. [NEED_CITE: steel grade equivalence between EN 10219 and ASTM A500] Third-party inspection by SGS or BV is frequently specified in EPC contracts for material traceability and dimensional verification before shipment.
Steel Grade Selection and ERW Process Fundamentals
The galvanized square and rectangular steel tube we produce covers three major steel grade systems: Chinese GB (Q195–Q345), European EN (S235–S355), and American ASTM (A500 Grade B/C/D, A53 Grade A/B). Within the EN system, S235JR provides adequate strength for general building frames, while S355J2H offers higher yield strength and guaranteed impact toughness at sub-zero temperatures — critical for bridges or outdoor structures in cold climates. The Q-series grades (Q235, Q345) are widely used in domestic Chinese projects and Belt & Road infrastructure, with mechanical properties broadly comparable to S235 and S355 respectively. [NEED_CITE: mechanical properties comparison between Q235 Q345 and S235 S355]
The ERW (Electric Resistance Welded) process forms the tube from hot-rolled or cold-rolled steel strip, welding the seam through electrical resistance without filler metal. This method is cost-effective for large-volume production of square and rectangular sections with tight dimensional tolerances. Cold-rolled strip produces smoother surfaces and more precise dimensions, while hot-rolled strip allows thicker walls. After forming and welding, the tubes pass through a galvanizing bath — either pre-galvanized (strip coated before forming) or post-galvanized (finished tube dipped) — depending on the zinc coating weight specified. The zinc layer (30–275 g/m²) provides corrosion protection proportional to its thickness: lighter coatings suit indoor or temporary structures, while heavier coatings are specified for marine or industrial environments.
Wall thickness tolerance directly affects both theoretical weight and structural performance. Negative tolerance (thinner than nominal) reduces material cost but may compromise load capacity if the design relies on nominal dimensions. Our in-house laboratory verifies wall thickness, coating weight, and mechanical properties against the relevant standard before release.
The Hidden Cost of Wrong Steel Grade or Missing Certification
Ordering galvanized square and rectangular steel tube without confirming the steel grade equivalence can lead to costly rework. If the structural design specifies S355J2H but the supplier delivers S235JR, the tubes may pass visual inspection but fail the engineer’s load calculation review — forcing replacement of already-installed members. Similarly, shipping to the EU without a valid CE certificate under EN 10219 means the cargo cannot be legally used in construction, regardless of physical quality. [NEED_CITE: consequences of non-compliant steel certification in EU construction projects] Material traceability gaps — missing heat numbers on the tubes or mismatched mill test certificates — can halt project acceptance and trigger third-party re-testing at the buyer’s expense.
Why Procure Galvanized Square and Rectangular Steel Tube from Xin Jiyuan
We operate three dedicated production lines in Jinan, manufacturing galvanized square and rectangular steel tube in over 2,800 specifications — from 10 mm small sections to 1000 mm large structural members, with wall thicknesses up to 28 mm and custom non-standard sizes available. Our proprietary sharp-corner rectangular tube technology, covered by 41 invention patents, produces tight internal radii that improve connection fit-up and structural aesthetics — a capability that has filled multiple gaps in the global market since we introduced it. Every shipment is verified by our in-house physical and chemical laboratory, with full mill test certificates documenting chemical composition and mechanical properties per the specified standard.
We hold CE certification under EN 10210/EN 10219 for EU market access, ISO 9001:2015 quality management, Singapore FPC for Southeast Asian projects, and third-party verification by SGS and BV. As a designated supplier for multiple state-owned enterprises and listed companies, we have exported to 50+ countries across the EU, North America, India, Southeast Asia, and the Middle East since 2013. Our professional loading team optimizes container utilization for square and rectangular sections — nesting smaller tubes inside larger ones to reduce freight cost — and coordinates door-to-door logistics with full tracking.
Documentation & Compliance
- Mill test certificate documenting Q235/S355/ASTM A500 chemical composition and mechanical properties per EN 10219 or ASTM A500
- CE certificate under EN 10210/EN 10219 for galvanized square and rectangular steel tube exported to EU member states
- ISO 9001:2015 quality management system certificate covering production and inspection processes
- SGS or BV third-party inspection report verifying dimensions, zinc coating weight, and surface quality
- Material traceability by heat number stamped on each tube, matching the mill test certificate
- Customs documentation package: packing list, bill of lading, certificate of origin, and commercial invoice
Packaging, Loading & Delivery
- Galvanized square and rectangular steel tube bundled with steel strips and edge protectors to preserve the zinc coating during ocean transit
- Seaworthy packaging with waterproof wrapping for heavy-gauge sections (wall thickness above 10 mm) to prevent condensation damage
- Container loading optimization: smaller square tubes nested inside larger rectangular sections to maximize 20ft or 40ft container utilization
- Custom cut-to-length service available for 1–12 m standard lengths, with saw-cut ends deburred and protected
- Heat number and steel grade stenciled on each bundle, with shipping marks matching the packing list and bill of lading
- Logistics options: FOB Qingdao, CIF destination port, or DDP door-to-door delivery with real-time tracking
Request a Quotation for Your Galvanized Square and Rectangular Steel Tube Project
Submit your specifications — section size, wall thickness, steel grade, quantity, and destination port — via email or WhatsApp, and we will respond within 12 hours with a detailed quotation including unit price, delivery time, payment terms, and applicable certifications. For non-standard sizes or sharp-corner rectangular tubes, we provide custom engineering drawings and production feasibility confirmation before order placement.
Get Your Galvanized Square and Rectangular Steel Tube Quote with Mill Test Certificate
Send your inquiry to admin@sdxjysteel.com or contact us via WhatsApp at +86 188 5315 7756 with your specifications and destination to receive a competitive factory-direct quotation and full documentation package.
Frequently Asked Questions
Q: What is the difference between EN 10219 and EN 10210 for galvanized square and rectangular steel tube?
A: EN 10219 covers cold-formed welded hollow sections produced at ambient temperature, while EN 10210 covers hot-finished welded and seamless hollow sections formed at elevated temperatures. The production method affects the material’s mechanical properties, residual stress distribution, and dimensional tolerances. Your project specification or structural engineer will indicate which standard applies.
Q: Can you produce non-standard sizes or sharp-corner rectangular tubes?
A: Yes. Beyond our 2,800+ standard specifications, we manufacture custom non-standard sizes and proprietary sharp-corner rectangular tubes with tight internal radii. This technology, covered by our invention patents, improves connection fit-up for structural frames and architectural applications. MOQ for custom sizes is negotiable based on specification complexity.
Q: What zinc coating weight should I specify for my project?
A: The zinc coating weight (30–275 g/m²) depends on the corrosion environment. Light coatings (30–60 g/m²) suit indoor or temporary structures. Medium coatings (90–150 g/m²) are typical for outdoor building frames and scaffolding. Heavy coatings (200–275 g/m²) are specified for marine, industrial, or high-humidity environments. We can advise based on your project conditions.
Q: Do you provide third-party inspection and certification for EU customs clearance?
A: Yes. We hold CE certification under EN 10210/EN 10219 for EU market access, and we arrange SGS or BV third-party inspection upon request. Our mill test certificates, packing lists, and certificates of origin are prepared to meet EU customs requirements. We have extensive export experience to 50+ countries and can guide you through documentation requirements for your specific destination.
Q: How do you optimize container loading for square and rectangular tubes?
A: Our loading team uses specialized nesting techniques — placing smaller square tubes inside larger rectangular sections — to maximize container utilization and reduce freight cost per ton. We provide loading plans and photos before shipment for your confirmation. For large projects, we coordinate multi-container shipments with staggered delivery schedules to match your site progress.
