Description
Factory-direct hollow sections, no broker markup — XJY Structure produces S355 and Q235 galvanized square and rectangular steel tubes from our own steel mill through to final fabrication, eliminating the gap between material supplier and fabricator.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | S355 / Q235 Galvanized Square and Rectangular Steel Tube |
| Product Type | Galvanized Square and Rectangular Steel Tube (Hollow Section) |
| Steel Grade | Q195, Q215, Q235, Q345, 10#, 20#, 45#, 16Mn, A53 (A/B), S355, St37, St42, St52 |
| Standard | BS EN, GB, AISI, ASTM, DIN, JIS |
| Section Shape | Square / Rectangular / Round |
| Size Range | 10mm – 1000mm (outer diameter or side length) |
| Wall Thickness | 0.6 – 28mm |
| Length | 1 – 12m or customized |
| Technique | Hot Rolled / Cold Rolled / ERW |
| Surface Treatment | Galvanized (Zinc Coating 30–275g/m²), Bare, Oiled, Color Paint, 3PE |
| Ends | Plain, Beveled, Threaded with couplings or sockets; plastic caps and steel rings available |
| Application | General engineering structures, fencing, construction frames, machinery, scaffolding, furniture, cars, bridges, ships, boilers, pressure vessels |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Infrastructure | Building frames, columns, beams, platform supports, stairway structures |
| Industrial & EPC Projects | Factory warehouse frames, conveyor support structures, pipe rack systems |
| Fencing & Scaffolding | Perimeter fencing posts, scaffolding uprights, temporary access structures |
| Machinery & Equipment | Machine frames, equipment bases, hydraulic support columns |
| Marine & Bridges | Bridge handrail posts, ship deck structures, corrosion-prone environment supports |
What Wall-Thickness Tolerance Costs on a Structural Frame Order
Tight wall-thickness control on a Galvanized Square and Rectangular Steel Tube Supplier order prevents on-site rework and structural recalculation.
When galvanized hollow sections arrive at a Lagos warehouse with wall thickness drifting below the specified 0.6mm minimum, the structural engineer must either reject the lot or recalculate load-bearing capacity — neither option is cheap. Buyers sourcing from fragmented supply chains often discover tolerance gaps only after the container is sealed, because the fabricator sourced raw material from a third-party mill with no traceability link. A Galvanized Square and Rectangular Steel Tube Supplier that controls the full chain from slab to finished tube eliminates this uncertainty. [NEED_CITE: EN 10219 cold-formed hollow section dimensional tolerance requirements]
Matching Hollow Sections to Structural Frame and Scaffolding Applications
A Galvanized Square and Rectangular Steel Tube Supplier serving EPC and construction projects must deliver sections that hold dimensional accuracy under welding heat and resist corrosion in tropical or coastal environments. The 30–275g/m² zinc coating range covers light indoor framing through to heavy outdoor exposure, while the 10–1000mm size range and 0.6–28mm wall thickness span everything from furniture frames to load-bearing columns. Our own mill produces the raw strip and plate, so every heat number on the mill test certificate traces back to our production line — not a broker’s paperwork trail.
Structural Code Compliance and Corrosion Environment Selection
Engineering specifications for structural hollow sections typically reference EN 1993-1-1 for load-bearing design and EN 10210 or EN 10219 for hot-finished or cold-formed hollow sections respectively. Selecting Q235 for general construction frames or S355 for higher-load applications directly affects section modulus and deflection limits. In coastal or industrial atmospheres, hot-dip galvanized coating at 275g/m² provides decades of corrosion protection without maintenance, while 3PE coating suits buried or submerged conditions. For EU import projects, CE marking under EN 10210/EN 10219 is mandatory for structural steel — without it, customs clearance stalls. [NEED_CITE: CE EN 10219 structural hollow section compliance for European market]
Steel Grade Equivalence and Manufacturing Process Explained
The Q-series (Q195–Q345) follows the Chinese GB standard system, where the number indicates minimum yield strength in MPa. The S-series (S355, St37, St42, St52) follows European EN standards, while A53 and A500 follow ASTM for the North American market. A Galvanized Square and Rectangular Steel Tube Supplier must map these grades correctly: Q235 roughly corresponds to S235JR and ASTM A36, while Q345 aligns with S355 and A572 Gr. 50. ERW (Electric Resistance Welded) process suits medium-wall sections with consistent weld seam quality, while hot-rolled process handles heavier walls up to 28mm. Hot-dip galvanizing at 30–275g/m² provides metallurgical zinc-iron bonding that outperforms electro-galvanized coating in outdoor exposure, and the coating weight is selected based on atmospheric corrosion category per ISO 12944.
Hidden Costs of Procuring Without Verified Certification
Ordering galvanized hollow sections without verified mill test certificates and third-party inspection reports creates cascading costs: customs rejection at the destination port due to missing CE documentation, structural inspection failure when zinc coating thickness falls below specification, and project schedule delays from re-procurement. A Galvanized Square and Rectangular Steel Tube Supplier that provides complete documentation — from heat number traceability to coating thickness reports — prevents these hidden costs before they materialize. [NEED_CITE: steel grade equivalence between EN and ASTM standards for structural applications]
Why Project Teams Source from XJY Structure
Our vertically integrated facility combines steel production with structural fabrication under one roof, meaning the raw material for your S355 galvanized tubes originates from our own mill — not a third-party trader. We hold CE EN 10210/EN 10219 certification for European market compliance, ISO 9001 quality management, and accept SGS/BV/TÜV third-party inspection on every order. Our 2,800+ specification range covers the full 10–1000mm size and 0.6–28mm wall thickness scope, so non-standard dimensions can be produced without splitting orders across multiple suppliers. Certified welding procedures (WPS/PQR) and qualified welders ensure that any fabrication work — cutting, drilling, welding — maintains structural integrity. Professional container loading with timber separators and edge protectors preserves the galvanized coating during ocean transit, a lesson learned from early shipment damage that cost us an entire container.
Documentation & Compliance
- Mill test certificate documenting S355JR or Q235B chemical composition and mechanical properties per EN 10219 or GB/T 6728
- CE certificate covering EN 10210 hot-finished and EN 10219 cold-formed structural hollow sections for EU customs clearance
- ISO 9001 quality management certificate covering the full production process from raw material to finished galvanized tube
- SGS or BV third-party inspection report verifying zinc coating thickness (30–275g/m²) and dimensional tolerance
- Full material traceability by heat number from our own steel mill through to finished product
- Export documentation package including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- Galvanized square and rectangular tubes bundled with steel strips and edge protectors to preserve the zinc coating during ocean transit
- Plastic caps fitted on tube ends to prevent moisture ingress and edge damage for galvanized and painted surface treatments
- Container loading optimized for 1–12m lengths with timber separators preventing direct tube-to-tube contact and coating abrasion
- Heat number and steel grade stenciled on each bundle for on-site identification and traceability verification
- FOB, CIF, and DDP shipping terms available with professional oversized cargo loading for large-section tubes up to 1000mm
- Custom cut-to-length service available for 1–12m requirements with saw-cut precision and deburred edges
Start Your Inquiry with Drawings and Specifications
Submit your project drawings (PDF/DWG), steel grade requirements, section dimensions, and destination port to receive a detailed quotation including material, fabrication, coating, packing, and shipping costs within 24 hours. Our engineering team will review shop drawings and confirm compliance with EN 10210/EN 10219 or ASTM standards before production begins.
Request a Quotation with Mill Test Certificate
Share your specifications and required standards to receive pricing and complete documentation.
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
