Description
Direct Mill Supply for ASTM A500 Projects — Every ASTM A500 Gr.B welded square steel tube rolls from our own ERW lines in Jinan, shipped with full mill test certificates and no trading markup.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | ASTM A500 Welded Square Steel Tube |
| Product Type | Welded Square Steel Tube (ERW) |
| Steel Grade | Gr.B, S235, S275, S355, STK400 |
| Standard | ASTM A500, ASTM A53, GB/T 3091 |
| Section Shape | Square |
| Size Range | 19×19 – 800×800 mm |
| Wall Thickness | 1 – 30 mm |
| Length | 5.8 / 6 / 11.8 / 12 m |
| Technique | ERW (Electric Resistance Welded) |
| Surface Treatment | Black / Galvanized / Varnish / Bare |
| Tolerance | ±1% |
| Ends | Plain ends |
| Application | Construction structure / Building frames / Curtain wall / Support tubes |
| MOQ | 5 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & EPC | Building frames, column supports, roof trusses for commercial and industrial projects |
| Facade & Curtain Wall | Vertical and horizontal mullions, architectural framing for glass curtain wall systems |
| Infrastructure | Support tubes for sound barriers, highway sign gantries, bridge handrails |
| Steel Structure Fabrication | Primary and secondary structural members cut and welded into portal frames |
What Tolerance Drift Costs When You Order 800×800 Square Tubes for a Portal Frame
A ±1% side deviation on an 800 mm square tube means 8 mm of unexpected gap at every welded connection.
On large-section ASTM A500 Gr.B welded square steel tube orders for portal frames and heavy building structures, even small tolerance shifts compound across dozens of connection nodes. Fabricators end up grinding, re-fitting, or scrapping pieces — burning through schedule buffer and weld consumables. [NEED_CITE: dimensional tolerance requirements for cold-formed structural hollow sections per ASTM A500] When the mill cannot hold consistent wall thickness across the full 1–30 mm range, theoretical weight calculations diverge from actual delivered weight, creating cost disputes at the container level.
Matching Wall Thickness and Grade to Structural Load Paths
For curtain wall framing in the 19×19 to 150×150 mm range, Gr.B or S235 delivers adequate load capacity with minimal weight. Once the project moves to primary columns or crane-support beams in the 300×300–800×800 range, upgrading to S355 or STK400 provides higher yield capacity without increasing section size. Our ERW lines produce the full 19×19–800×800 mm range in a single facility, so structural engineers can specify one ASTM A500 Gr.B welded square steel tube supplier for both secondary purlins and main columns — eliminating cross-mill tolerance mismatches at connection points.
Engineering Compliance and Certification Alignment
Structural frames designed to AISC or EN 1993 require traceable mill test certificates linking each bundle to its heat number. ASTM A500 Gr.B is the default grade for North American construction; S235/S275/S355 covers EN 10219 projects in Europe and the Middle East; STK400 serves JIS-specified work in Southeast Asia. [NEED_CITE: steel grade equivalence mapping between ASTM A500 and EN 10219 standards] Surface treatment selection — galvanized for outdoor exposure, black or bare for indoor structural use, varnish for temporary corrosion protection during transit — must align with the project environment before the mill schedules the run.
ERW Weld Integrity and Surface Treatment Logic
ERW welding produces a clean, consistent longitudinal seam ideal for square sections in the 19–800 mm range, with lower cost and tighter dimensional control than SSAW for this size bracket. Galvanized coating adds 40–80 μm of zinc protection for exterior curtain wall supports and infrastructure tubes exposed to weather. Black finish or bare delivery suits indoor building frames where post-fabrication painting or fireproofing will be applied on site. Wall thickness tolerance of ±1% across the 1–30 mm range keeps theoretical weight calculations reliable for structural load analysis.
Hidden Costs of Unverified Grade and Tolerance
An ASTM A500 Gr.B welded square steel tube that arrives with actual yield strength below the Gr.B minimum fails structural inspection and triggers full-bundle rejection — not just the defective pieces. Missing or incomplete mill test certificates delay customs clearance in regulated markets, especially for EU projects requiring CE marking under EN 10219. [NEED_CITE: customs documentation requirements for structural steel imports into EU and GCC markets] Negative tolerance beyond the ±1% specification reduces actual load-bearing capacity while the invoice still charges by theoretical weight — a cost that only surfaces after fabrication begins.
Why Project Procurement Teams Source ASTM A500 Gr.B Welded Square Steel Tube from Our Jinan Mill
Our three ERW production lines cover the full 19×19–800×800 mm range in wall thicknesses up to 30 mm, meaning your 800×800 main columns and 50×50 purlins roll from the same facility under the same quality system. The in-house physical and chemical laboratory tests every heat for composition and mechanical properties before release — no outsourced reports. We hold CE certification under EN 10210 and EN 10219, ISO 9001:2015, and Singapore FPC, with SGS and BV third-party inspection available on request. Custom non-standard lengths and sizes are available with low MOQ, and our loading team uses dedicated jigs and edge protectors to prevent corner damage during container transit — a lesson learned the hard way on an early Middle East shipment.
Documentation & Compliance
- Mill Test Certificate documenting Gr.B / S355 chemical composition and mechanical properties per ASTM A500 or EN 10219, linked to heat number
- CE certificate covering EN 10210 / EN 10219 for projects requiring EU regulatory compliance
- ISO 9001:2015 quality management certificate covering the full ERW production process
- SGS or BV third-party inspection report available before container sealing
- Material traceability from heat number through rolling, welding, and final bundling
- Full customs document set: packing list, bill of lading, certificate of origin
Packaging, Loading & Delivery
- ERW square tubes bundled with steel strips and padded edge protectors to preserve surface finish — galvanized coatings receive extra corner guards to prevent zinc scraping
- Plain-end tubes stacked with interleaved separators to avoid surface contact damage during ocean transit
- Container loading optimized for 5.8 m and 11.8 m lengths to maximize 20ft and 40ft GP utilization, with weight distribution calculated per bundle
- Custom cutting to project-specific lengths available before bundling, with cut-end deburring
- Each bundle tagged with heat number, steel grade (Gr.B / S355 / STK400), size, and length for site identification
- FOB, CIF, and DDP terms available with full export documentation and container tracking
Getting Your ASTM A500 Gr.B Welded Square Steel Tube Quote Ready for Project Approval
Submit your size range, wall thickness, steel grade, surface treatment, quantity, and destination port — we return a detailed quotation with unit pricing, production lead time, and shipping terms within 12 hours. Mill test certificates and third-party inspection arrangements are confirmed before contract signing, so your engineering team has full documentation for project approval.
Request Your ASTM A500 Gr.B Welded Square Steel Tube Quotation
Send your specifications, steel grade, and destination to receive pricing, mill test certificate samples, and container loading plans.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.sdxjypipe.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@sdxjypipe.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
Frequently Asked Questions
Q: Can you produce ASTM A500 Gr.B welded square steel tubes in non-standard sizes outside the 19×19–800×800 mm range?
A: Yes. Our three ERW production lines cover 2,800+ specifications, and we accept custom non-standard sizes and lengths beyond the standard range. MOQ for custom sizes remains accessible for project orders.
Q: What surface treatment options are available for ASTM A500 Gr.B welded square steel tubes?
A: We offer black finish, hot-dip galvanized, varnish coating, and bare delivery. Galvanized is recommended for outdoor and coastal applications; black or bare suits indoor structural frames where post-fabrication coating will be applied.
Q: Do you provide CE certification for ASTM A500 Gr.B welded square steel tubes shipped to the EU?
A: Yes. We hold CE certification under EN 10210 and EN 10219, and can supply full EN-compliant mill test certificates and third-party inspection reports from SGS or BV for EU customs clearance.
Q: How do you prevent damage to welded square steel tubes during container loading and ocean transit?
A: Every container load uses dedicated steel jigs, edge protectors, and interleaved separators. Galvanized tubes receive additional corner guards. Our loading team inspects each bundle before sealing, and we provide loading photos before departure.
Q: What is the minimum order quantity for ASTM A500 Gr.B welded square steel tubes?
A: The standard MOQ is 5 tons. For custom non-standard sizes or specific length requirements, we work with project teams to find practical batch sizes that balance production efficiency with project needs.
