Description
Direct Mill Supply, No Middlemen — XJY Structure produces Q235 and Q355 rectangular steel tubes on our own rolling lines, giving you mill-direct pricing and full heat-level traceability from slab to finished section.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235 / Q355 Rectangular Steel Tube |
| Product Type | Rectangular Steel Tube / Hollow Section |
| Steel Grade | Q195, Q235, Q355, S195, S235JR, S355JR, A53 Grade A, A53 Grade B, A500 Grade A, A500 Grade B, A500 Grade C, STK400, SS400, ST42.2, S355J0H, S355J2H |
| Standard | EN10219, EN10210, GB/T 6728, JIS G3466, ASTM A500, ASTM A53, ASTM A36 |
| Section Shape | Rectangular / Square |
| Size Range | Rectangular: 20×40 mm – 300×500 mm; Square: 20×20 mm – 500×500 mm |
| Wall Thickness | 1.2 – 20 mm |
| Length | 3 – 12 m (random or cut to size) |
| Technique | Hot Rolled / ERW |
| Surface Treatment | Black (oiled / non-oiled), Pre-galvanized (40–80 g/m²), Hot-dip Galvanized (200–600 g/m²) |
| Tolerance | ±1% |
| Ends | Plain |
| Application | Steel structures, construction frames, solar support structures, fence posts, greenhouse frames, machinery, building materials |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| EPC & General Contracting | Warehouse portal frames, factory column grids, mezzanine platforms, conveyor support structures |
| Renewable Energy | Solar panel mounting racking, inverter stands, cable trench frames |
| Agriculture & Horticulture | Greenhouse skeleton tubes, livestock fencing posts, irrigation framework |
| Infrastructure | Highway sign gantries, sound barrier posts, utility pole base sections |
| Machinery & Equipment | Machine base frames, crane boom sections, equipment skids |
What Wall-Thickness Tolerance Costs on a Structural Frame Order
A ±1% tolerance on a Q355 rectangular steel tube means the difference between passing dimensional inspection and scrapping an entire container at the port.
Overseas buyers routinely discover that wall thickness on hollow sections drifts well below the specified value when the fabricator sources material from unverified third-party mills. I once stood at a Vietnamese warehouse site with a caliper, watching a third-party inspector reject a full shipment because 1.5 mm specified walls measured 1.0 mm on multiple pieces. The structural engineer nearly scrapped the entire order. When you order a Q235 Q355 rectangular steel tube manufacturer that controls its own rolling lines, you eliminate the gap between what the mill cert says and what the caliper reads. [NEED_CITE: EN 10219 cold-formed hollow section dimensional tolerance requirements]
Matching Section Dimensions to Structural Load Paths
Rectangular hollow sections carry bending loads efficiently because material is distributed away from the neutral axis on both planes. On a warehouse portal frame, a 200×100 mm Q355 section at 8 mm wall thickness handles rafter moments that a round tube of equivalent weight cannot match without larger overall dimensions. Our size range from 20×40 mm up to 300×500 mm covers everything from purlin bracing to primary column sections, and the ±1% wall tolerance keeps engineer-calculated load capacities valid across every piece in the shipment. When a Q235 Q355 rectangular steel tube manufacturer rolls both hot-pressed and ERW sections in-house, you can mix light gauge bracing tubes and heavy structural columns in a single purchase order without coordinating multiple suppliers.
Engineering Compliance Across EN, ASTM, and GB Frameworks
A structural frame designed to EN 1993-1-1 requires material certified to EN10219 or EN10210, while the same project’s mezzanine platform in a US-specified zone may call for ASTM A500 Grade B or C. Our grade coverage — Q235, Q355, S235JR, S355JR, A500 Grade A through C, JIS STK400 and SS400 — means one purchase order satisfies mixed-standard drawings without splitting shipments between Chinese and European mills. For EU-bound projects, CE marking under EN10210 and EN10219 is mandatory for customs clearance, and our factory holds the required production control certification. [NEED_CITE: steel grade equivalence mapping between EN 10219 and ASTM A500 standards]
Decoding the Grade Designations on Your Drawing
Q235 and Q355 follow the Chinese GB/T 1591 system where the number indicates minimum yield strength in MPa; S235JR and S355JR follow the European EN 10025 designation with JR denoting room-temperature Charpy impact energy at 27 J. ASTM A500 Grade B and C serve the North American structural hollow section market, with Grade C offering higher yield for seismic and heavy-load applications. When your drawing specifies S355J0H or S355J2H, the J0 and J2 suffixes indicate impact test temperatures of 0°C and −20°C respectively — critical for outdoor structures in cold climates. Hot-rolled sections offer thicker walls suited to primary load-bearing frames, while ERW processing delivers tighter dimensional accuracy for secondary structures and architectural applications. Surface treatment selection follows the environment: black oiled for indoor or paintable structures, pre-galvanized at 40–80 g/m² for sheltered outdoor use, and hot-dip galvanized at 200–600 g/m² for coastal or industrial corrosion zones. [NEED_CITE: hot-dip galvanizing coating weight selection for corrosive environments]
The Hidden Cost of Unverified Material on Site
Accepting a rectangular tube shipment without verified mill test certificates means the structural engineer cannot sign off on load calculations, regardless of whether the physical dimensions look correct. Material sourced from spot-market traders often carries certificates that do not match the heat number stamped on the tube, creating traceability gaps that fail third-party inspection. On a Q235 Q355 rectangular steel tube manufacturer with integrated production, every bundle carries a heat number traceable to the original slab chemistry and mechanical test results. When customs authorities in the EU or Middle East request EN 10204 3.1 certificates and the documentation does not align with the physical goods, the container sits at port accumulating demurrage while the supplier scrambles to source valid paperwork — or worse, the shipment gets rejected outright. [NEED_CITE: EN 10204 3.1 inspection document requirements for structural steel]
Why Buyers Consolidate Rectangular Tube Procurement at XJY Structure
Our vertically integrated operation means the same facility that rolls the raw tube also fabricates the finished structural components — columns, beams, trusses, and connection assemblies — under one quality management system. With over 2,800 specifications held in inventory, we can ship mixed-size container loads for a warehouse project without waiting for individual size production runs. Every shipment leaves Jinan with a complete documentation package: EN 10204 3.1 mill test certificates, CE marking compliance for EN10219 and EN10210, ISO 9001 quality records, and weld procedure qualifications certified to AWS and EN standards. Our engineering team reviews shop drawings before fabrication begins, identifying dimension conflicts and material optimization opportunities that prevent costly rework at the installation stage. Professional loading plans account for oversized section geometry, ensuring that 300×500 mm columns and 20×40 mm bracing tubes arrive without surface damage or deformation.
Documentation & Compliance
- Mill test certificate documenting Q235 and Q355 chemical composition, yield strength, and tensile properties per heat number, issued to EN 10204 3.1 format
- CE certificate confirming EN10210 hot-finished and EN10219 cold-formed hollow section compliance for EU market entry
- ISO 9001 quality management certificate covering incoming slab inspection through final dimensional and surface treatment verification
- SGS or BV third-party inspection report available for pre-shipment wall thickness, coating weight, and dimensional checks
- Full material traceability linking each bundle heat number to slab chemistry, rolling records, and mechanical test results
- Export documentation package including packing list, bill of lading, and certificate of origin for destination customs clearance
Packaging, Loading & Delivery
- Rectangular tubes bundled with high-tensile steel strips at intervals matched to section length, with 12 m random lengths and cut-to-size orders separated by protective dividers
- Hot-dip galvanized Q355 sections wrapped with edge protectors and moisture-resistant paper to preserve the 200–600 g/m² zinc coating during ocean transit
- Pre-galvanized and black oiled tubes nested by size range to maximize 20ft and 40ft container payload, with 300×500 mm sections loaded flat to prevent corner deformation
- Cut-to-size orders at 3–12 m lengths prepared with plain ends and beveled options available upon request, bundled separately with size labels
- Each bundle tagged with heat number, steel grade (Q235 / Q355 / S355JR), section dimensions, and wall thickness for site identification
- FOB, CIF, and DDP shipping terms available with professional oversized cargo loading plans and full container tracking to destination port
Requesting a Fabrication-Ready Quotation
Send your project drawings in PDF or DWG format along with specified steel grades, section dimensions, wall thickness, surface treatment preference, and destination port. We respond within 24 hours with a detailed quotation covering material, fabrication, coating, packing, and shipping costs, plus a shop drawing timeline and production schedule. Our engineering team will review your drawings for material optimization and fabrication sequencing before you commit to a contract.
Get Your Rectangular Tube Quotation with Mill Test Certificates
Submit your specifications, steel grade requirements, and quantity to receive a detailed quotation and EN 10204 3.1 mill test certificate samples.
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
