Description
Factory-direct Q235B ERW round steel pipe — raw material from our own steel mill flows directly into ERW welding lines, eliminating third-party sourcing gaps and ensuring full heat-number traceability from billet to finished pipe.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235B ERW Round Steel Pipe |
| Product Type | ERW Round Steel Pipe |
| Steel Grade | Q195, Q235B, Q345B, 10#, 20#, 45#, 16Mn, ASTM A36, ASTM A53, ASTM A106, ASTM A500, SS400, St37, St52, S235JR, S355JR |
| Standard | ASTM A53, ASTM A106, ASTM A500, GB/T 3091-2001, GB/T 13912-2002, BS 1387, ASTM F1083 |
| Section Shape | Round |
| Size Range | OD 10–1000 mm |
| Wall Thickness | 1–80 mm |
| Length | 1–12 m |
| Technique | ERW / Hot Rolled |
| Surface Treatment | Hot Rolled / Cold Rolled / Oiled / Non-oiled |
| Tolerance | ±1% |
| Ends | Plain / Beveled |
| Application | Fluid transport / Construction structure / Scaffolding / Greenhouse structure / Fence post / Machinery parts / Curtain wall |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| EPC & Industrial Projects | Fluid transport piping for water, gas, and oil systems; process piping in chemical and fertilizer plants |
| Construction & Infrastructure | Structural columns and beams in building frames; scaffolding systems; curtain wall support structures |
| Agriculture & Commercial | Greenhouse frame tubing; fence post systems; furniture and display rack frames |
| Machinery & Equipment | Hydraulic cylinder sleeves; conveyor roller tubes; machinery part fabrication |
Why Negative Tolerance on Thin-Wall ERW Pipe Triggers Site Rejection
A ±1% tolerance claim means nothing without mill-level dimensional control at every coil.
When buyers source Q235B ERW round steel pipe from trading companies who subcontract to multiple mills, wall thickness consistency becomes a lottery. A 2 mm nominal wall running at minus 15% on random batches will pass factory gate but fail third-party inspection at destination port. The cost is not the pipe — it is three days of idle production line, air freight for replacement stock, and a damaged relationship with the project owner. [NEED_CITE: EN 10219 dimensional tolerance requirements for welded hollow sections]
Matching Wall Thickness to Structural and Fluid Service Demands
The 1–80 mm wall thickness range in Q235B ERW round steel pipe covers both ends of the procurement spectrum. Thin-wall sections (1–3 mm) serve greenhouse frames, fence posts, and furniture where weight and cost matter more than pressure rating. Mid-range walls (4–10 mm) handle scaffolding, curtain wall supports, and conveyor structures requiring predictable load capacity. Thick-wall sections (10–80 mm) move into machinery parts and structural columns where machining and welding integrity become critical. Our own steel mill produces the coil and plate that feeds directly into ERW lines, so the same heat number on the mill test certificate traces back to the original slab — no broken chain between material supplier and pipe fabricator.
Engineering Compliance Across ASTM, EN, and GB Frameworks
Structural engineers specifying Q235B ERW round steel pipe often need cross-referencing between standards. Q235B maps closely to ASTM A36 and S235JR in yield behavior, while Q345B aligns with ASTM A572 Gr50 and S355JR for higher-load applications. For projects in the EU, EN 10219 compliance governs cold-formed welded sections; for North American EPC work, ASTM A53 and A500 define the acceptance criteria. Our engineering team reviews shop drawings against these standards before fabrication begins, checking that the specified steel grade, wall thickness, and surface treatment match the environmental exposure and connection details. Third-party inspection by SGS, BV, or TÜV is available at any production stage to verify dimensional accuracy and weld quality. [NEED_CITE: steel grade equivalence tables between GB, ASTM, and EN systems]
How ERW Process and Steel Grade Selection Affect Performance
ERW (Electric Resistance Welding) forms the round profile from coil or plate and welds the seam through electrical resistance heating — no filler metal, consistent weld geometry, and cost efficiency for OD 10–1000 mm ranges. The Q-series grades (Q195, Q235B, Q345B) follow the Chinese GB system where the number indicates minimum yield strength in MPa; ASTM A36, A53, and A500 serve the same structural roles in North American specifications; S235JR and S355JR are the European EN equivalents with guaranteed impact energy at specified temperatures. Surface treatment choice depends on the service environment: oiled finish protects during storage and transit for indoor or coated applications; hot-rolled surface suits structural work where paint or galvanizing will follow; cold-rolled finish provides tighter dimensional control for precision machining. The ±1% tolerance applies across the full OD and wall range, but achieving it consistently requires in-process dimensional checks and NDT testing on every weld seam — not just end-of-line sampling.
The Hidden Cost of Unverified Material on Structural Projects
Ordering Q235B ERW round steel pipe based on price alone, without verified mill test certificates and third-party inspection, creates risks that surface only at site acceptance. Material that fails chemical composition checks cannot be regraded — it must be scrapped or returned. Wall thickness outside the declared tolerance triggers rejection under ASTM A53 or EN 10219 dimensional requirements, delaying project handover. Missing heat-number traceability blocks customs clearance in markets requiring EN 10204 3.1 or 3.2 certificates. The rework cost — cutting out installed sections, re-welding, re-coating — always exceeds the original price difference between verified and unverified supply. [NEED_CITE: ASTM A53 dimensional and chemical requirements for ERW pipe]
Why Buyers Choose Our Vertically Integrated Supply
Our steel mill produces the raw material that feeds directly into our ERW pipe production lines — there is no gap between coil supplier and pipe fabricator. This vertical integration means one quality system covers the entire process from slab to finished pipe, and one point of accountability handles any technical query or claim. We hold over 2,800 specifications in stock across round, square, and rectangular sections, so mixed-size orders ship from a single source without consolidating from multiple suppliers. Certified welding procedures (WPS/PQR) and qualified welders support any custom fabrication work, while our engineering team provides shop drawing review and material optimization before production starts. Complete quality documentation — mill test certificates, dimensional reports, coating reports, and weld maps — ships with every order. Professional loading plans handle oversized and heavy pipe bundles, with full export documentation and tracking through to site delivery.
Documentation & Compliance
- Mill test certificate documenting Q235B chemical composition and mechanical properties per GB/T 700, with heat number traceability to the original slab
- CE certificate confirming compliance with EN 10219 for cold-formed welded structural hollow sections where specified
- ISO 9001 quality management system certificate covering the full production process from raw material to finished pipe
- SGS or BV third-party inspection report available at any production stage, verifying dimensional accuracy, weld quality, and surface treatment
- Full material traceability package linking each pipe bundle to its heat number, production date, and test results
- Complete customs documentation set: commercial invoice, packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- Q235B ERW round steel pipe bundled with steel strips in seaworthy packages, with edge protectors on oiled or coated surfaces to prevent damage during ocean transit
- Surface protection matched to treatment type: oiled pipes wrapped in waterproof paper; hot-rolled pipes bundled with anti-rust protection for open-yard storage at destination
- Container loading optimized for OD 10–200 mm pipes in 20ft and 40ft containers, with wooden cradles for longer lengths (6–12 m) to prevent bending
- Custom cutting to exact project lengths within the 1–12 m range, reducing on-site waste and welding joints
- Heat number and steel grade stenciled on each pipe end, with bundle tags matching the mill test certificate for easy site identification
- FOB, CIF, and DDP terms available, with professional logistics coordination for oversized cargo and door-to-door delivery to project sites
Getting Your Q235B ERW Round Steel Pipe Quote Ready for Production
Share your project drawings (PDF or DWG), specify the steel grade, OD, wall thickness, length, quantity, and destination port. Our team responds within 24 hours with a detailed quotation covering material, fabrication, coating, packing, and shipping costs — including shop drawing timeline and production schedule. Once drawings are approved and the contract signed, material procurement and production begin immediately, with full quality documentation prepared before shipment.
Start Your Q235B ERW Round Steel Pipe Inquiry Today
Send your specifications and drawings to receive a detailed quotation with mill test certificate preview and production timeline.
Contact:
- 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 Q235B compare to ASTM A36 and S235JR?
A: Q235B, ASTM A36, and S235JR are closely matched carbon structural steel grades with similar yield strength levels. Q235B follows the Chinese GB/T 700 standard, ASTM A36 follows the American ASTM A36/A36M standard, and S235JR follows the European EN 10025-2 standard. All three are suitable for general structural applications, and our engineering team can confirm equivalence for your specific project requirements.
Q: Can you provide third-party inspection before shipment?
A: Yes, we accept third-party inspection by SGS, BV, TÜV, or your nominated inspection agency at any production stage. The inspection covers dimensional accuracy, weld quality, surface treatment, and visual examination. The inspection report is included in the shipping documentation package.
Q: What surface treatment options are available for Q235B ERW round steel pipe?
A: We offer hot-rolled, cold-rolled, oiled, and non-oiled surface conditions. Oiled finish provides temporary rust protection during storage and transit. Hot-rolled surface is suitable for projects where painting or galvanizing will follow. Cold-rolled finish provides tighter dimensional control for precision applications. Galvanizing can be arranged as a secondary process if required.
Q: What is the typical production lead time for standard and custom sizes?
A: Standard sizes in stock ship within typical production lead times after contract confirmation. Custom sizes or non-standard lengths require additional production time depending on the specification and quantity. Our quotation includes a detailed production schedule so you can plan your project timeline accordingly.
Q: Do you provide shop drawing support for custom fabrication?
A: Yes, our engineering team reviews your project drawings and prepares shop drawings for approval before fabrication begins. We provide material optimization advice and fabrication sequencing to reduce waste and improve installation efficiency. This service is included in the quotation for custom orders.
