Description
Factory-Direct Pricing, No Middlemen — Every ASTM A500 GR.B rectangular hollow section rolls off our own ERW and seamless lines in Jinan, cutting agent markups from your landed cost.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | ASTM A500 GR.B Rectangular Steel Tube |
| Product Type | Rectangular Hollow Section (RHS) / Welded Square and Rectangular Steel Tube |
| Steel Grade | Gr.B, S355JRH, Q235B, Q345B, S235, S275, S355, STK400 |
| Standard | ASTM A500, ASTM A53, GB/T 3091, EN 10219, EN 10210, DIN |
| Section Shape | Square / Rectangular |
| Size Range | 15mm×20mm – 700mm×800mm |
| Wall Thickness | 1 – 30 mm |
| Length | 5.8m / 6m / 11.8m / 12m / Random Length |
| Technique | ERW Welded / Seamless |
| Surface Treatment | Black Painting / Galvanized / Varnish / Bare / Oiled |
| Tolerance | ±12.5% |
| Ends | Plain |
| Invoicing | By Theoretical Weight |
| Application | Construction structures / Building frames / Curtain walls / Support tubes / Structural pipe / Machinery / Scaffolding |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Industrial Construction | Portal frame columns and rafters for warehouses, factory sheds, and logistics centers |
| Commercial Building | Curtain wall mullions, facade support tubes, and canopy structures |
| Infrastructure | Bridge handrails, sound barrier posts, and highway sign gantries |
| Machinery & Equipment | Machine bases, conveyor frames, and hydraulic support structures |
| Scaffolding & Temporary Works | Load-bearing scaffolding uprights and bracing tubes |
What Wall-Thickness Tolerance Costs on a Structural Frame Order
A ±12.5% tolerance window on a 5mm-wall RHS means the thinnest legitimate tube still carries the design load — but only if every batch is verified.
I once watched a West African warehouse project stall for three weeks because the buyer’s SGS inspector found wall thickness clustering right at the negative tolerance edge on a 200×50 RHS shipment. The steel grade stamp said Gr.B, the mill certificate looked clean, but the actual load-bearing margin had evaporated. Fragmented sourcing from multiple traders without centralized quality control creates exactly this risk — each supplier ships to their own interpretation of “within tolerance,” and the structural engineer’s safety factor disappears into the gap. [NEED_CITE: EN 10219 cold-formed hollow section dimensional tolerance requirements]
How This RHS Matches Structural Frame Demands
The 15mm×20mm to 700mm×800mm size range covers everything from light-gauge curtain wall mullions to heavy portal frame columns. For industrial buildings in coastal or humid environments, specifying hot-dip galvanized ASTM A500 GR.B rectangular hollow section eliminates on-site painting delays and extends maintenance cycles. The ERW welded process delivers consistent corner geometry for moment-resisting connections, while seamless options handle higher point loads in machinery bases where weld-line integrity matters.
Engineering Compliance and Certification Requirements
Structural frames designed to EN 1993 or AISC specifications require traceable material certification — every heat number must link back to chemical composition and mechanical test data. For European projects, CE marking under EN 10210 (seamless) or EN 10219 (welded) is not optional; customs authorities in Germany, France, and the Netherlands routinely reject shipments lacking FPC documentation. [NEED_CITE: CE marking requirements for structural hollow sections under EN 10210 and EN 10219] The ASTM A500 GR.B rectangular hollow section we supply carries Lloyd’s CE certification alongside ISO 9001:2015 quality management, meaning your project compliance officer gets one document package covering both material conformity and factory audit status.
Steel Grade Selection and Manufacturing Process
Gr.B under ASTM A500 corresponds roughly to S275 in the EN system and Q235B in GB — all three sit in the mild structural steel range suitable for general framing. When your engineer specifies S355JRH or Q345B, you are moving into higher yield strength territory for longer spans or heavier roof loads. The ERW welded process forms the tube from coil, welding the seam longitudinally — cost-effective for standard structural sizes up to 30mm wall. Seamless production, available for heavier walls, eliminates the weld line entirely, which matters when the tube faces cyclic loading or internal pressure. Surface treatment choice follows environment: black painted or oiled for indoor dry use, hot-dip galvanized for outdoor or corrosive atmospheres, bare for sites where the buyer handles final coating.
Hidden Costs of Buying the Wrong Grade or Unverified Material
Ordering Q235B when the drawing calls for S355JRH does not show up until the structural inspector measures deflection under load — by then, replacement means dismantling erected frames and delaying handover. Missing mill test certificates trigger customs holds at destination ports; I have seen containers sit for weeks because the importer could not produce EN 10204 3.1 documentation. [NEED_CITE: material certificate requirements under EN 10204 for structural steel] Negative tolerance abuse — where actual wall thickness drifts below the legitimate tolerance floor — reduces section modulus and compromises fire resistance ratings. These failures do not appear in the purchase order; they surface during erection, inspection, or worse, under service load.
Why Buyers Choose Our Mill Direct
We run three production lines simultaneously in Jinan, holding 2,800+ specifications in ready stock so your urgent 20-ton order for 200×100×6mm Gr.B RHS ships from the yard, not from a production queue. Factory-direct pricing means no trading company margin sits between your budget and our mill price — volume discount tiers activate for long-term partners. Every batch leaves with original mill test certificates tied to heat number, and we welcome SGS or BV third-party inspection before container sealing. Our export team handles consolidated loading when you mix RHS, SHS, round pipe, and H-beam in one container, optimizing weight distribution and documentation for CIF or DDP delivery to 50+ countries.
Documentation & Compliance
- Mill test certificate documenting ASTM A500 Gr.B chemical composition and mechanical properties per heat number, issued to EN 10204 3.1 format
- CE certificate covering EN 10219 cold-formed welded hollow sections and EN 10210 seamless hollow sections, with Factory Production Control audit report
- ISO 9001:2015 quality management system certificate covering design, production, and inspection of structural hollow sections
- SGS or BV third-party inspection report available on request, covering dimensional checks, visual inspection, and witness testing before shipment
- Material traceability sheet linking each bundle to heat number, steel grade (Gr.B / S355JRH / Q235B / Q345B), and production date
- Full customs document package: commercial invoice, packing list, bill of lading, certificate of origin, and fumigation certificate where required
Packaging, Loading & Delivery
- ASTM A500 GR.B rectangular hollow sections bundled with steel strips and edge protectors, sized to match 5.8m / 6m / 11.8m / 12m lengths for standard 20ft and 40ft containers
- Galvanized RHS bundles wrapped with waterproof paper and plastic film to preserve zinc coating during ocean transit and prevent white rust formation
- Container loading plans optimized by our export team to maximize weight utilization for heavy-wall (10–30mm) sections while respecting axle weight limits at destination
- Custom cutting to fixed length available for 15mm×20mm through 700mm×800mm sizes, reducing on-site waste and welding time for your erection crew
- Each bundle tagged with heat number, steel grade (Gr.B / S355JRH / Q235B), size, and length for immediate identification at port and on job site
- FOB Jinan/Qingdao, CIF, or DDP delivery options with real-time tracking and professional customs clearance support for destination ports worldwide
How to Request a Quote with Mill Test Verification
Send your specification list — size, wall thickness, steel grade, surface treatment, quantity, and destination port — and receive a bulk quotation with volume discount pricing, delivery timeline, and sample mill test certificate within 12 hours. For non-standard sizes outside the 15×20mm to 700×800mm range, we provide custom production schedules with confirmed lead times. Confirm your certification requirements (CE, SGS/BV inspection, certificate of origin) upfront so the documentation package ships with the first container.
Frequently Asked Questions
Q: How does ASTM A500 Gr.B compare to EN 10219 S355JRH and GB Q235B?
A: ASTM A500 Gr.B is a mild structural steel grade commonly used in North American projects. It roughly corresponds to S275 in the EN system and Q235B in GB. S355JRH and Q345B offer higher yield strength for heavier spans. We supply all these grades under one roof and provide cross-reference documentation for your engineer.
Q: Can I get SGS or BV third-party inspection before shipment?
A: Yes. We welcome SGS, BV, or other accredited third-party inspectors to verify dimensional accuracy, surface quality, and witness testing at our Jinan facility before container sealing. Inspection reports issue directly to your name.
Q: What is the MOQ for non-standard sizes outside your ready stock range?
A: Our minimum order quantity is 1 Ton per size. For non-standard dimensions or custom lengths outside 5.8m / 6m / 11.8m / 12m, production lead times apply. Send your specification list for a confirmed schedule.
Q: How do you handle container loading when I mix RHS, SHS, and round pipe?
A: Our export team designs consolidated loading plans that maximize container weight capacity while protecting surface finish. We coordinate documentation for multi-product shipments so your customs broker receives one complete package.
Get Your ASTM A500 GR.B Rectangular Hollow Section Quote with Mill Test Certificate
Submit your size, grade, quantity, and destination port to receive factory-direct pricing and sample certification within 12 hours.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.sdxinjiyuan.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@sdxinjiyuan.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
