Description
Factory-Direct SHS Production — Vertically integrated steel mill and fabrication workshop producing ASTM A500 welded square steel tube from raw billet to finished section, eliminating third-party material sourcing gaps.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | ASTM A500 Welded Square Steel Tube |
| Product Type | Welded Square Steel Tube / Square Hollow Structural Section (SHS) |
| Steel Grade | Gr.B, S235, S275, S355, STK400, Q235B, Q345B |
| Standard | ASTM A500, ASTM A53, GB/T 3091 |
| Section Shape | Square |
| Size Range | 19mm×19mm – 800mm×800mm |
| Wall Thickness | 1 – 30 mm |
| Length | 5.8m / 6m / 11.8m / 12m / Random Length |
| Technique | ERW (Electric Resistance Welded) |
| Surface Treatment | Black Painting / Galvanized / Varnish / Bare |
| Tolerance | ±1% |
| Ends | Plain |
| Application | Construction structures / Building frames / Curtain wall supports / Structural pipe / Machinery frames |
| MOQ | 5 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Commercial Construction | Building frames, column systems, roof truss supports for warehouses and retail structures |
| Industrial Facilities | Machinery frames, equipment support platforms, conveyor structure bases |
| Architectural Engineering | Curtain wall support systems, facade structural pipe, canopy frameworks |
| Infrastructure Projects | Bridge handrail posts, sound barrier supports, signage gantry columns |
What Wall-Thickness Tolerance Costs on a Structural Frame Order
Tolerance drift on welded square hollow sections triggers rework, rejected inspections, and schedule delays on international projects.
When buyers source ASTM A500 welded square steel tube from fragmented suppliers who purchase raw material from third-party mills, the material certification chain breaks down. The mill test certificate references a heat number that cannot be traced back to the actual production batch. Dimensional checks on arrival reveal wall thickness falling outside the ±1% tolerance band — particularly on larger sections above 400mm where ERW weld seam consistency becomes critical. [NEED_CITE: EN 10219 cold-formed hollow section dimensional tolerance requirements] Third-party inspectors flag the entire lot, and the buyer faces the choice of accepting non-conforming material or waiting weeks for replacement shipments while the construction schedule stalls.
Matching SHS Dimensions to Structural Frame Requirements
The 19mm×19mm through 800mm×800mm size range of ASTM A500 welded square steel tube covers everything from light-gauge curtain wall supports to heavy-duty column sections in industrial buildings. For EPC contractors assembling warehouse frames in Southeast Asia or the Middle East, the availability of both 5.8m and 12m lengths reduces on-site welding joints and accelerates erection speed. The ±1% wall thickness tolerance ensures that connection plates and bolt groups fit as designed — a detail that matters when shop drawings specify moment-resisting connections on S355 grade sections. Our own steel mill produces the raw coil, and our fabrication division welds and forms it into finished SHS, so every tube leaving the facility carries traceable documentation from billet to bundle.
Engineering Compliance and Certification Pathways
Structural engineers specifying ASTM A500 Gr.B for North American projects or EN-equivalent S355 for European construction require documentation that satisfies local building codes and customs authorities. The ASTM A500 welded square steel tube we produce meets the chemical composition and testing requirements of ASTM A500, ASTM A53, and GB/T 3091, with cross-reference equivalence available between ASTM A500 Gr.B, EN S355JR, and GB Q345B for multi-standard project compliance. [NEED_CITE: steel grade equivalence between EN and ASTM standards] For EU market shipments, CE certification under EN 10210 and EN 10219 confirms that the hollow sections meet European fabrication and structural performance requirements. Surface treatment selection — hot-dip galvanized for coastal or high-humidity environments, black painted for interior structural use, or bare for projects where the contractor handles coating on-site — is matched to the project’s corrosion exposure classification during the quotation stage.
Understanding ERW Welding and Steel Grade Selection
The ERW (Electric Resistance Welded) process forms square hollow sections by cold-forming flat steel strip into a square profile and welding the longitudinal seam through electrical resistance heating — without filler metal. This produces a clean, consistent weld seam suitable for structural applications where the ASTM A500 welded square steel tube serves as load-bearing columns, beams, or bracing members. Steel grade selection directly influences structural performance: S235 provides adequate strength for light framing and non-critical supports, S275 serves medium-load applications such as mezzanine floors and equipment platforms, while S355 delivers higher yield strength for primary structural frames in multi-story buildings and long-span industrial facilities. The Q-series grades (Q235B, Q345B) follow the Chinese GB standard system and correspond closely to S235 and S355 respectively in mechanical properties. Wall thickness ranges from 1mm for lightweight architectural applications to 30mm for heavy structural columns, with the ±1% tolerance maintained across the full range through in-process dimensional monitoring.
Hidden Costs of Sourcing Without Verified Traceability
Purchasing ASTM A500 welded square steel tube from traders who source from unknown mills creates risks that surface only during project inspection or customs clearance. Material certificates may reference test results from a different heat number than the actual shipment — a discrepancy that EN 10204 3.1 and 3.2 certification frameworks are designed to prevent. [NEED_CITE: EN 10204 inspection document types for steel products] Wall thickness drifting into heavy negative tolerance reduces the section’s load-bearing capacity below the engineer’s design assumption, potentially triggering structural safety concerns during third-party inspection. Non-conforming material at the destination port means customs holds, demurrage charges, and the cost of emergency replacement shipments — expenses that far exceed any initial price saving from an unverified supplier.
Why Procurement Teams Choose Our Integrated Production
Our facility operates its own steel production lines with 2,800+ raw material specifications in stock, meaning the coil that becomes your ASTM A500 welded square steel tube never passes through an external trader’s warehouse. Every batch undergoes chemical composition and mechanical property testing in our in-house laboratory before forming begins, and the resulting mill test certificate traces each bundle back to its specific heat number. We hold CE certification for EN 10210 and EN 10219, ISO 9001 quality management registration, and accommodate SGS or BV third-party inspection before shipment — documentation packages that satisfy EU, North American, and Middle Eastern project requirements. For orders requiring non-standard dimensions or specific length combinations to optimize container loading, our fabrication team reviews shop drawings and proposes cutting plans that minimize waste and reduce freight cost per ton. Professional loading teams handle oversized sections and prepare complete export documentation including packing lists, bills of lading, and certificates of origin for smooth customs clearance at the destination port.
Documentation & Compliance
- Mill test certificate documenting ASTM A500 Gr.B chemical composition and mechanical properties per heat number, conforming to EN 10204 3.1 type
- CE certificate confirming EN 10219 cold-formed hollow section compliance for EU market structural applications
- ISO 9001 quality management system certificate covering the full production process from raw material receipt to finished SHS dispatch
- SGS or BV third-party inspection report available upon request, covering dimensional checks, visual weld inspection, and coating thickness measurement
- Material traceability report linking each bundle’s heat number to the originating steel production batch and test results
- Complete customs documentation package including packing list, bill of lading, certificate of origin, and commercial invoice formatted to destination country requirements
Packaging, Loading & Delivery
- ASTM A500 welded square steel tube bundled with steel strips and edge protectors, sized to fit standard 20ft and 40ft containers based on section dimensions and 5.8m/6m/12m lengths
- Galvanized SHS packaged with waterproof interlayer separators to preserve zinc coating integrity during ocean transit and prevent white rust formation
- Black painted or varnished tubes wrapped in protective film at weld seams and corners to prevent coating damage during handling and transport
- Custom cutting to project-specific lengths available, with bundled off-cuts labeled by heat number and steel grade for site traceability
- Each bundle marked with heat number, steel grade (Gr.B/S355/Q345B), section size, wall thickness, and production date for on-site identification
- FOB, CIF, and DDP shipping terms supported, with professional loading plans for oversized sections up to 800mm×800mm and complete export documentation prepared before vessel departure
Starting Your ASTM A500 Welded Square Steel Tube Inquiry
Submit your project drawings, required steel grades, section dimensions, wall thickness, surface treatment preference, and destination port — our engineering team responds within 24 hours with a detailed quotation including material cost, fabrication charges, coating options, and shipping arrangements. For projects requiring shop drawing review or non-standard dimension confirmation, we provide technical support before contract signing to ensure the ASTM A500 welded square steel tube specification matches your structural design and local code requirements.
Request Your Quotation and Mill Test Certificate
Share your project specifications, steel grade requirements, and target quantity to receive a detailed quotation with full documentation package details.
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
Frequently Asked Questions
Q: What is the equivalence between ASTM A500 Gr.B, EN S355JR, and GB Q345B?
A: These three steel grades follow different standard systems but share similar mechanical property ranges. ASTM A500 Gr.B conforms to the American standard system, EN S355JR follows the European EN standard, and Q345B follows the Chinese GB/T standard. For multi-standard projects, we provide cross-reference documentation confirming chemical composition and mechanical property alignment between these grades, allowing engineers to specify the appropriate grade for their local building code while sourcing from a single production facility.
Q: Can third-party inspection be arranged before shipment?
A: Yes. We accommodate SGS, BV, or other internationally recognized inspection agencies to conduct dimensional checks, visual weld seam inspection, coating thickness measurement, and review of mill test certificates before the ASTM A500 welded square steel tube leaves our facility. The inspection report becomes part of your complete documentation package for project handover and customs clearance.
Q: What surface treatment options are available for different project environments?
A: We offer hot-dip galvanized coating for projects in coastal or high-humidity environments where corrosion resistance is critical, black painting for interior structural applications where the steel will be enclosed or protected, varnish coating for moderate environmental exposure, and bare (uncoated) delivery for projects where the contractor or end user handles surface treatment on-site. The quotation includes coating cost options so you can compare based on your project’s corrosion classification.
Q: How do you handle non-standard dimensions or project-specific length requirements?
A: Our fabrication workshop supports custom cutting to project-specific lengths beyond the standard 5.8m, 6m, 11.8m, and 12m options. Share your shop drawings or cutting lists, and our engineering team proposes a plan that optimizes container loading and minimizes material waste. MOQ for custom lengths remains 5 Tons, and we provide updated mill test certificates reflecting the actual dimensions supplied.
Q: What documentation is included for EU market projects requiring CE certification?
A: For EU shipments, we provide CE certification confirming EN 10219 cold-formed hollow section compliance, mill test certificates conforming to EN 10204 3.1 format with full heat number traceability, declaration of performance documents, and complete customs paperwork including certificate of origin. The documentation package is prepared to satisfy both the importing country’s customs requirements and the project’s structural engineering verification standards.
