Description
Direct Mill Supply for Structural SHS — ASTM A500 Gr.B welded square steel tube produced under ISO 9001:2015 with original mill test certificates and full heat-number traceability for every shipment.
Technical Specifications + Markdown 表格
| Parameter | Value |
|---|---|
| Designation | ASTM A500 Welded Square Steel Tube |
| Product Type | Welded Square Hollow Structural Section (SHS) |
| Steel Grade | Gr.B, S235, S275, S355, STK400, CS (Carbon Steel) |
| 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 / DRL / SRL |
| Technique | ERW (Electric Resistance Welded) |
| Surface Treatment | Black Painting / Galvanized / Varnish / Bare |
| Tolerance | ±1% |
| Ends | Plain |
| Processing Service | Bending, Cutting |
| Application | Construction structure / Building frames / Curtain wall / Support tubes / Structural pipe / Machinery frames |
| MOQ | 5 Tons |
| Origin | China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Commercial Construction | Building frames, column supports, roof trusses for warehouses and industrial plants |
| Architectural Facade | Curtain wall mullions, decorative structural frames, canopy supports |
| Infrastructure | Bridge handrails, highway sign gantries, sound barrier posts |
| Machinery & Equipment | Conveyor frames, machine bases, equipment support structures |
| Scaffolding & Temporary Works | Scaffold towers, shoring props, temporary support frames |
What Wall-Thickness Tolerance Costs on a Structural Frame Order
Tolerance deviations on welded square tubes trigger rework, inspection holds, and schedule delays — not just weight discrepancies.
When procurement teams source ASTM A500 Gr.B welded square steel tube across mixed suppliers, negative tolerance practices often surface only after third-party inspection at the fabrication yard. A batch specified at 3.0mm wall arriving at 2.5mm actual means load calculations no longer match as-built conditions, forcing engineers to either reject the shipment or redesign connections. Missing mill test certificates compound the problem — without heat numbers and chemical composition records, customs clearance stalls and project handover documentation remains incomplete [NEED_CITE: EN 10219 cold-formed hollow section dimensional tolerance requirements].
How Dimensional Range Matches Structural Frame Requirements
The 19×19mm to 800×800mm side length range with 1–30mm wall thickness covers everything from light-gauge curtain wall mullions to heavy column sections in industrial buildings. For ASTM A500 Gr.B welded square steel tube used in building frames, the ±1% tolerance ensures predictable connection geometry — bolt holes align, weld preparations fit, and fabrication drawings hold true. Our ERW process maintains consistent corner radii across the full size range, which matters when square tubes meet at moment connections or bolted end-plate joints.
Engineering Compliance and Certification Pathways
Structural designs referencing ASTM A500 require mill test certificates documenting chemical composition and mechanical properties per the standard’s Gr.B classification [NEED_CITE: ASTM A500 cold-formed welded and seamless carbon steel structural tubing specification]. For projects in Europe or regions adopting EN standards, S235/S275/S355 grades conform to EN 10219 requirements, while STK400 serves JIS-specified projects. Surface treatment selection — black painted for indoor frames, hot-dip galvanized for outdoor exposure, or bare for field-coating — must align with corrosion environment assessments before fabrication begins. Custom cutting to exact lengths reduces on-site waste and welding time, though minimum order quantities apply for non-standard dimensions.
Steel Grade Selection and ERW Welding Principles
ASTM A500 Gr.B provides minimum yield strength suitable for general structural applications, while S355 offers higher load capacity for heavy-duty frames. The ERW welding process creates a longitudinal seam through electric resistance heating — proper weld annealing ensures the seam matches base metal properties, which is why original mill test certificates must include weld zone testing results. Black painting provides basic corrosion protection for indoor use, while galvanized coating extends service life in humid or coastal environments. Wall thickness directly affects both weight and load-bearing capacity; specifying exact requirements prevents suppliers from applying excessive negative tolerance that compromises structural performance [NEED_CITE: steel grade equivalence between ASTM A500 and EN 10219 standards].
Hidden Costs of Incorrect Material Procurement
Ordering the wrong steel grade or accepting undocumented negative tolerance creates cascading expenses: failed third-party inspections delay fabrication, missing certificates block customs clearance, and material substitution requires engineering reapproval. ASTM A500 Gr.B welded square steel tube without proper heat-number traceability cannot be verified against mill records, leaving structural engineers unable to certify as-built conditions. Projects facing these issues typically absorb costs through expedited replacement shipments, re-fabrication of rejected components, and extended construction schedules [NEED_CITE: structural steel procurement documentation requirements for project handover].
Why Procurement Teams Choose Our Mill Direct Supply
We produce ASTM A500 Gr.B welded square steel tube in our own facility with ISO 9001:2015 certified quality management, eliminating broker markups and ensuring every heat number traces back to our rolling records. Our in-house laboratory generates mill test certificates documenting chemical composition and mechanical properties for each batch — no certificates sourced from third parties or fabricated after shipment. The full size range from 19×19mm to 800×800mm with wall thickness up to 30mm means mixed-specification orders ship together, reducing your procurement complexity. Custom cutting service processes tubes to exact project lengths before shipment, minimizing on-site waste. Professional heavy-cargo logistics teams handle flatbed loading and container stuffing to prevent transit damage, with complete export documentation prepared for smooth customs clearance at destination ports.
Documentation & Compliance
- Mill test certificate documenting ASTM A500 Gr.B chemical composition and mechanical properties per heat number
- CE certificate confirming EN 10219 compliance for S235/S275/S355 grades shipped to European markets
- ISO 9001:2015 quality management certificate covering production and inspection processes
- SGS or BV third-party inspection report available upon request for pre-shipment verification
- Material traceability documentation linking each tube bundle to specific heat numbers and rolling records
- Complete customs documents including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- ASTM A500 Gr.B welded square steel tube bundled with steel strips and edge protectors to prevent surface damage during ocean transit
- Galvanized tubes packed with plastic wrapping to preserve zinc coating integrity throughout shipping and storage
- Black painted tubes separated by protective interleaving to maintain coating continuity before fabrication
- Container loading optimized for 6m and 12m lengths to maximize payload while respecting weight restrictions
- Each bundle marked with heat number, steel grade, size, and length for immediate site identification
- FOB, CIF, and DDP shipping terms available with professional flatbed and open-top container handling
How to Initiate Your Procurement Inquiry
Submit your ASTM A500 Gr.B welded square steel tube requirements including steel grade, size dimensions, wall thickness, total quantity, and destination port — we respond within 12 hours with detailed pricing, mill test certificate samples, and shipping options. For custom cutting or non-standard specifications, share your fabrication drawings and we confirm feasibility with processing timelines.
Request Your ASTM A500 Welded Square Steel Tube Quote
Send specifications to receive pricing, mill test certificate samples, and delivery options.
Company: Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.xjyplate.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@xjyplate.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
Frequently Asked Questions
Q: How do ASTM A500 Gr.B, S235JR, S355JR, and STK400 steel grades compare for structural applications?
A: ASTM A500 Gr.B serves general structural requirements in North American projects, while S235JR/S275JR/S355JR follow European EN 10219 standards with increasing yield strength levels. STK400 meets JIS specifications for Japanese-standard projects. We supply all grades from the same production facility with full mill test certificates for each standard.
Q: Can I verify mill test certificates and heat numbers before shipment?
A: Yes, we provide original mill test certificates documenting chemical composition and mechanical properties for every batch. You can verify heat numbers against our production records, and third-party inspection through SGS or BV is available for pre-shipment quality confirmation.
Q: What is the minimum order quantity for custom cut-to-size square tubes?
A: Standard MOQ is 5 tons for regular stock sizes. Custom cutting to specific lengths incurs processing fees, and minimum quantities depend on the final dimensions requested. Share your cutting list and we confirm exact requirements.
Q: When should I specify galvanized versus black painted versus bare surface treatment?
A: Hot-dip galvanized coating suits outdoor exposure, coastal environments, or high-humidity conditions requiring long-term corrosion protection. Black painting provides basic protection for indoor structural frames. Bare tubes work when field coating or additional surface treatment will be applied after delivery based on final installation environment.
Q: How are heavy square tubes packed and loaded to prevent damage during shipping?
A: ASTM A500 Gr.B welded square steel tube is bundled with steel strips and edge protectors. Galvanized tubes receive additional plastic wrapping to preserve the zinc coating. Container loading is optimized for your specific lengths to maximize payload while preventing transit damage. Professional heavy-cargo logistics teams handle all loading operations.
Get Your ASTM A500 Welded Square Steel Tube Quote Today
Submit your specifications including steel grade, dimensions, quantity, and destination to receive detailed pricing with mill test certificate samples and shipping options.
Company: Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.xjyplate.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@xjyplate.com
