Description
Direct Mill Supply — Full ASTM A500 Gr.B / S355JRH RHS & SHS inventory from in-house steel production
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Gr.B / S355JRH / Q235B / Q345B Welded Square & Rectangular Hollow Section |
| Product Type | Welded Square and Rectangular Steel Tube (RHS / SHS) |
| Steel Grade | Gr.B (ASTM A500), S355JRH, Q235B, Q345B, S235, S275, S355, STK400 |
| Standard | ASTM A500, ASTM A53, GB/T 3091, EN 10219, JIS G3466 |
| Section Shape | Square / Rectangular |
| Size Range | 15 mm × 20 mm – 700 mm × 800 mm |
| Wall Thickness | 1 – 30 mm |
| Length | 5.8 m / 6 m / 11.8 m / 12 m / Random Length |
| Technique | ERW Welded |
| Surface Treatment | Black Painting / Galvanized / Varnish / Bare / Oiled |
| Tolerance | ±12.5% |
| Ends | Plain |
| Application | Steel structures / Construction frames / Curtain wall / Support tubes / Building structures / Fertilizer equipment |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Commercial & Industrial Construction | Building frames, column-beam assemblies, mezzanine platforms, warehouse portal frames |
| Infrastructure & Civil Engineering | Bridge support structures, highway sign gantries, utility pole bases, conveyor supports |
| EPC & General Contracting | Prefabricated steel modules, equipment support frames, pipe rack structures |
| Machinery & Equipment Manufacturing | Crane booms, hydraulic frames, agricultural machinery chassis, fertilizer processing equipment |
| Curtain Wall & Façade Systems | Mullion tubes, transom members, structural glazing supports |
What Negative Tolerance Really Costs on a Structural Frame Order
A 2% wall-thickness deviation on a 250×100 RHS can trigger full-batch rejection at third-party inspection.
When buyers source ASTM A500 Gr.B rectangular hollow section from fragmented suppliers, material certificates often arrive without heat-number traceability back to the rolling mill. I have seen entire containers of hollow section turned away at the port because measured wall thickness fell outside the permitted tolerance band — the paperwork said one thing, the caliper said another. Without vertically integrated production, there is no way to verify whether the steel plate feeding the ERW line matches the grade stamped on the certificate. [NEED_CITE: EN 10219 dimensional tolerance requirements for cold-formed hollow sections]
Matching Hollow Section Profiles to Structural Load Paths
An ASTM A500 Gr.B rectangular hollow section delivers closed-section torsional rigidity that open profiles cannot match, making it the preferred choice for column-beam moment frames and bracing members in multi-storey buildings. The ERW welding process produces a continuous longitudinal seam that, when inspected per approved WPS and verified through NDT, provides joint integrity comparable to the parent metal. For projects spanning multiple code jurisdictions — say, an EPC warehouse build in Southeast Asia requiring both ASTM and EN compliance — sourcing S355JRH and Gr.B from a single mill eliminates the risk of mixed-grade shipments arriving on site.
Engineering Compliance Across ASTM, EN, and GB Standards
Structural engineers specifying ASTM A500 Gr.B rectangular hollow section for North American projects expect mill test certificates conforming to ASTM A53 and AISC 207 documentation standards, while EU-bound shipments must carry CE marking under EN 10219 with factory production control audited to ISO 9001. The Q345B grade, widely used in Belt & Road infrastructure projects across Africa and Central Asia, maps closely to S355 in yield classification but requires separate chemical composition verification for welding procedure qualification. Surface treatment selection — galvanized for coastal corrosion environments, black painted or oiled for indoor structural frames — directly affects both long-term durability and initial landed cost. [NEED_CITE: steel grade equivalence mapping between ASTM A500 and EN 10219]
Understanding ERW Welding and Grade Selection for Hollow Sections
The ERW (Electric Resistance Welding) process forms square and rectangular profiles by cold-bending steel strip into shape and fusing the seam through high-frequency current — this method suits medium-wall thickness ranges from 1 mm to 30 mm and delivers consistent dimensional accuracy across long production runs. Steel grade selection directly governs structural performance: S235 serves light-duty framing where weight optimization matters, S355JRH provides higher yield strength for heavily loaded columns and crane-supporting beams, while Q345B offers a cost-effective alternative in markets where GB standards are specified. The ASTM A500 Gr.B rectangular hollow section supplier offering multiple grade options from one production line allows project teams to consolidate procurement without sacrificing code compliance. Wall thickness tolerance under EN 10219 permits ±10% for most profiles, but invoicing by theoretical weight means buyers must confirm whether negative tolerance deviations affect actual load-bearing capacity versus billing weight. Surface treatment adds another layer: hot-dip galvanizing provides 60–80 μm zinc coating for aggressive environments, while black painting or bare oiled finish suits indoor applications where corrosion risk is minimal.
Hidden Costs of Sourcing Without Mill Traceability
Purchasing ASTM A500 Gr.B rectangular hollow section from trading companies without direct mill access creates a documentation chain with multiple handoff points — each transfer introduces the possibility of mixed heat numbers, substituted grades, or certificates that cannot be verified against the original rolling records. When a structural engineer requests EN 10204 3.2 third-party inspection and the material fails, the cost of replacement, re-shipping, and project delay far exceeds any initial price saving from a non-integrated supplier. Negative tolerance beyond the standard allowance reduces actual section modulus, meaning the tube carries less load than the design calculation assumed — a safety concern that only surfaces during load testing or, worse, after structural failure. [NEED_CITE: consequences of material traceability gaps in structural steel procurement]
Why Integrated Mill-to-Fabrication Sourcing Eliminates Procurement Risk
XJY Structure operates three production lines within its own steel mill, holding over 2,800 raw material specifications in stock — this means the steel strip feeding the ERW forming station is the same material documented in the mill test certificate, with full heat-number traceability from slab to finished tube. Every ASTM A500 Gr.B rectangular hollow section produced carries certified WPS and PQR welding records, in-process dimensional inspection reports, and coating thickness measurements, all compiled into a single QC documentation package. The in-house engineering team reviews shop drawings before production begins, flagging potential fabrication conflicts and suggesting material optimization that reduces waste. For EU projects, CE certification under EN 10219 is maintained with annual factory audits; for Middle East and African infrastructure contracts, SGS and BV third-party inspections are arranged before shipment at the buyer’s request. Professional loading teams plan container stowage for 6 m and 12 m lengths to maximize cube utilization while protecting surface finish during ocean transit.
Documentation & Compliance
- Mill Test Certificate documenting Gr.B chemical composition and mechanical properties per ASTM A500, with heat number traceability to in-house steel production
- CE Certificate under EN 10219 for S355JRH rectangular hollow section, required for structural steel customs clearance in EU member states
- ISO 9001 Quality Management System certificate covering the full production chain from raw material procurement through ERW welding and surface treatment
- SGS or BV Third-Party Inspection Report available upon request, verifying dimensional accuracy, wall thickness, and coating quality before container sealing
- Material Traceability Register linking each bundle to its original heat number, rolling date, and chemical composition test results
- Export Documentation Package including commercial invoice, packing list, bill of lading, and certificate of origin for destination-country customs clearance
Packaging, Loading & Delivery
- ERW welded S355JRH and Gr.B rectangular hollow sections bundled with galvanized steel strips at maximum 3-ton intervals, with edge protectors preventing zinc coating damage on galvanized finishes during transit
- Surface protection matched to treatment type: oiled bare tubes wrapped in waterproof cloth, galvanized sections separated by rubber spacers to avoid zinc scratching, black painted tubes loaded with nylon slings
- Container loading optimized for 6 m and 12 m standard lengths in 20ft and 40ft open-top or flat-rack containers, with nested smaller profiles (15×20 mm to 100×100 mm) filling void spaces to reduce freight cost per ton
- Custom cut-to-length service available for random length orders, with saw-cut ends deburred and marked with heat number, steel grade, and section dimensions in weatherproof ink
- Bundle identification tags displaying steel grade (Gr.B / S355JRH / Q345B), section size, wall thickness, heat number, and gross/net weight for rapid site identification
- Shipping terms FOB Qingdao, CIF destination port, or DDP project site, with full container tracking and door-to-door logistics coordination for EPC contractors
How to Initiate a Structural Steel Procurement Inquiry
Submit project drawings in PDF or DWG format along with required steel grades, section sizes, total tonnage, and destination port to receive a detailed quotation including material cost, ERW fabrication, surface treatment, and ocean freight within 24 hours. The engineering team will review shop drawings for compliance with ASTM A500 or EN 10219 standards and confirm mill test certificate availability before production begins. Third-party inspection by SGS or BV can be arranged at the fabrication stage for buyers requiring independent quality verification.
Request Your ASTM A500 Gr.B Rectangular Hollow Section Quotation
Send your project specifications, steel grade requirements, and destination port to receive pricing with full mill test certificate documentation.
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: How does ASTM A500 Gr.B compare to EN 10219 S355JRH in mechanical properties?
A: ASTM A500 Gr.B and S355JRH belong to different standard systems but serve similar structural applications. Gr.B is specified under the ASTM framework for North American projects, while S355JRH conforms to EN 10219 for European and international markets. Both grades provide adequate yield strength for building frames and structural supports, though exact mechanical equivalence requires cross-reference against the specific project specification. Mill test certificates are issued per the standard under which the material is produced.
Q: What documentation is included with each shipment of ASTM A500 Gr.B rectangular hollow section?
A: Every shipment includes Mill Test Certificates with chemical composition and mechanical properties, heat number traceability linking each bundle to its production batch, dimensional inspection reports, and surface treatment records. For EU projects, CE certification under EN 10219 is provided. Third-party inspection reports from SGS or BV can be arranged before shipment at the buyer’s request. Complete export documentation including packing list, bill of lading, and certificate of origin is standard.
Q: Can you produce non-standard sizes outside the 15×20 mm to 700×800 mm range?
A: The standard production range covers 15 mm × 20 mm to 700 mm × 800 mm with wall thickness from 1 mm to 30 mm. For project-specific dimensions outside this range, the engineering team reviews the requirement against mill capability and can provide custom fabrication quotes. Minimum order quantities for non-standard profiles may apply depending on the tooling and production setup required.
Q: How do you ensure wall thickness tolerance meets ASTM A500 requirements?
A: As a vertically integrated producer with in-house steel mill and ERW fabrication lines, XJY Structure controls the entire process from raw material to finished tube. In-process dimensional checks are performed at multiple stages during forming and welding. Each bundle is inspected for wall thickness, outer dimensions, and straightness before packing. Mill test certificates document compliance with the specified standard, and third-party inspection by SGS or BV can be witnessed by the buyer or their representative before shipment.
Q: What is the difference between theoretical weight invoicing and actual weight, and how does negative tolerance affect cost?
A: ASTM A500 Gr.B rectangular hollow section is invoiced by theoretical weight calculated from nominal dimensions and standard density. Permitted negative tolerance under the applicable standard means actual wall thickness may be slightly below nominal, but remains within code-allowed limits. Buyers should confirm whether the quotation is based on theoretical or actual weight, as this affects the final landed cost per ton. Full dimensional inspection reports are provided so buyers can verify compliance with tolerance requirements.
