Description
Factory-direct ASTM A500 GR.B square steel tube manufacturer — every batch verified by our in-house physical and chemical laboratory before container sealing.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | ASTM A500 GR.B Square Steel Tube |
| Product Type | Square Steel Tube / SHS (Square Hollow Section) |
| Steel Grade | ASTM A500 GR.B, S235, S275, S355, STK400 |
| 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 | Welded (ERW) / Seamless |
| Surface Treatment | Black Painting / Galvanized / Varnish / Bare |
| Tolerance | ±1% |
| Ends | Plain |
| Application | Construction structures, Building frames, Curtain wall framing, Support tubes, Structural pipe |
| MOQ | 5 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Commercial Construction | Building frames, column supports, roof truss structures |
| Architectural Facade | Glass curtain wall framing, exposed structural grids, decorative SHS columns |
| Industrial Machinery | Equipment support bases, conveyor frame structures, crane boom sections |
| Infrastructure | Bridge handrail posts, solar mounting structures, signage gantries |
What Negative Tolerance Really Costs on an ASTM A500 GR.B Structural Order
A ±1% tolerance enforced at the mill saves rework at the job site.
I once watched a full container of square tubes get rejected at a Middle Eastern port because the wall thickness drifted below the ASTM A500 GR.B minimum. The supplier had relied on theoretical weight instead of actual measurement. Our ASTM A500 GR.B square steel tube production runs dimensional checks on every bundle — side length, wall thickness, and straightness — before the mill test certificate is signed. When buyers source from multiple suppliers without verified tolerance control, they face customs holds, third-party re-inspection fees, and on-site welding mismatches that delay project handover. [NEED_CITE: ASTM A500 dimensional tolerance requirements for cold-formed hollow sections]
Matching SHS Dimensions to Curtain Wall and Frame Engineering
Architectural facade contractors need square profiles with consistent 90-degree corners and tight dimensional control — a 2mm deviation on a 200mm SHS can misalign an entire glass panel grid. Our ASTM A500 GR.B square steel tube covers 19×19mm to 800×800mm with ±1% tolerance, produced in both ERW welded and seamless routes to match structural load requirements. The ±1% tolerance means a 300×300×10mm tube stays within 297–303mm, which keeps bolt-hole alignment predictable for curtain wall bracket connections.
Structural Compliance and Surface Protection for Project Environments
Load-bearing frames for commercial buildings must conform to ASTM A500 GR.B yield requirements, while facade elements in coastal or industrial zones demand hot-dip galvanized or painted surfaces to resist corrosion before final cladding. Our ASTM A500 GR.B square steel tube ships with EN 10204 3.1 mill test certificates documenting chemical composition and mechanical properties, and we arrange SGS or BV third-party inspection for projects requiring independent verification. [NEED_CITE: ASTM A500 GR.B mechanical property requirements for structural hollow sections]
Steel Grade Selection and Production Route Logic
ASTM A500 GR.B sits in the mid-range structural category — higher strength than S235, comparable to Q345B in the GB system, and widely specified across North American and international projects. ERW welded production suits standard sizes up to 400mm with cost efficiency, while seamless processing handles heavy-wall demands above 20mm where internal pressure or point loading matters. Surface treatment choice follows the environment: bare tubes for indoor structural frames, black painting for temporary corrosion protection during transit, and hot-dip galvanized for outdoor exposure or buried support structures. Wall thickness selection directly affects load capacity — a 300×300 SHS at 10mm wall carries significantly more than the same section at 6mm, and negative tolerance beyond specification limits reduces actual section modulus.
Hidden Costs When Material Certification Fails at Customs
An ASTM A500 GR.B square steel tube without a valid mill test certificate or with incorrect grade marking will fail customs inspection in regulated markets — the entire shipment gets held, tested at buyer’s expense, or returned. Missing CE documentation blocks EU entry entirely, while grade substitution (shipping S235 against an A500 GR.B order) creates structural liability if the project engineer discovers the mismatch during foundation inspection. [NEED_CITE: steel grade equivalence verification between ASTM and EN standards]
Why Project Buyers Source ASTM A500 GR.B SHS From Our Mill
We produce ASTM A500 GR.B square steel tube on three dedicated lines covering over 2,800 specifications, so you source standard and non-standard sizes from one factory instead of splitting orders across multiple suppliers. Our in-house physical and chemical laboratory tests every heat number for yield strength, tensile properties, and composition before the mill test certificate issues — no outsourcing to third-party labs that adds days to your timeline. We hold Lloyd’s CE certification for EN 10219 and EN 10210, ISO 9001:2015 registration, and Singapore FPC approval, which clears customs across EU, Middle East, and Southeast Asian ports without additional documentation requests. For facade projects requiring true 90-degree corners, our patented sharp-corner rectangular tube technology eliminates the rounded radii that standard cold-forming leaves on SHS edges. Professional container loading with anti-damage measures prevents bending and surface scratches during ocean transit — I personally supervise loading plans for project orders to avoid the port-rejection mistakes I watched happen early in my career.
Documentation & Compliance
- Mill test certificate documenting ASTM A500 GR.B chemical composition (C, Mn, P, S) and mechanical properties per ASTM A500
- CE certificate per EN 10219 for cold-formed welded structural hollow sections, required for EU market entry
- ISO 9001:2015 quality management certificate covering production and inspection processes
- SGS or BV third-party inspection report available before container sealing for project-specific verification
- Material traceability by heat number linking each bundle to its production batch and test results
- Full customs documentation including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- ASTM A500 GR.B square steel tubes bundled with steel strips and edge protectors to maintain ±1% dimensional tolerance during ocean transit
- Galvanized SHS packed with plastic sheet separation to preserve zinc coating integrity and prevent white rust formation
- Container loading optimized for 6m and 12m lengths with wooden chocks preventing bundle shift and corner damage
- Custom cutting to project-specific lengths available, reducing on-site waste and welding time for curtain wall framing
- Heat number and steel grade stenciled on each bundle for site identification and traceability verification
- FOB, CIF, and DDP shipping terms with professional loading supervision and door-to-door logistics coordination
Start Your ASTM A500 GR.B SHS Procurement
Submit your size range, wall thickness, steel grade, surface treatment, and destination port — we return a detailed quotation with unit pricing, production lead time, and mill test certificate format within 12 hours. For non-standard dimensions or sharp-corner requirements, we provide custom engineering drawings and MOQ confirmation before production begins.
Request Quotation and Mill Test Certificate
Send your ASTM A500 GR.B square steel tube specifications to admin@sdxjypipe.com or contact us via WhatsApp at +86 188 5315 7756.
Frequently Asked Questions
Q: Can you provide ASTM A500 GR.B square steel tubes with third-party inspection before shipment?
A: Yes, we arrange SGS or BV inspection at our facility before container loading. The inspector verifies dimensions, wall thickness, surface quality, and reviews mill test certificates. You receive the inspection report with photos before the container seals.
Q: What is the MOQ for custom non-standard sizes outside your regular range?
A: Our standard range covers 19×19mm to 800×800mm with 1–30mm wall thickness. For non-standard dimensions, MOQ depends on the production setup required — typically 5 tons for sizes close to our regular production, higher for completely custom profiles. We confirm exact MOQ after reviewing your drawing.
Q: How do you ensure the wall thickness stays within ASTM A500 GR.B tolerance?
A: Every bundle undergoes dimensional measurement using calibrated ultrasonic thickness gauges and calipers. We test multiple points along the length and around the perimeter. Results are recorded on the mill test certificate. If any measurement falls outside ±1% tolerance, that piece is rejected before bundling.
Q: Can you supply both ERW welded and seamless ASTM A500 GR.B square steel tubes?
A: Yes. ERW welded production covers standard sizes efficiently, while seamless processing handles heavy-wall requirements where internal integrity matters. We recommend the production route based on your application — structural frames typically use ERW, while high-load or pressure applications may require seamless.
Q: What surface treatment do you recommend for outdoor curtain wall framing?
A: For outdoor facade applications, hot-dip galvanized provides long-term corrosion protection without painting. If the design requires a specific color or additional protection, we apply black painting as a base coat, then you can top-coat on site after installation. Bare tubes suit indoor or temporary structures where painting happens after fabrication.
