Description
Factory-Direct ERW Welded Steel Pipe — No middlemen, full mill test documentation included with every shipment.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235/Q345 ERW Welded Steel Pipe |
| Product Type | ERW Welded Steel Pipe |
| Steel Grade | Q195, Q235/Q235B, Q345/Q345B, S235JR, S275JR, S355JR, A53, SS400, St37, St52, 20#, 10#, 16Mn, ASTM A36, ASTM A500, ASTM A106 |
| Standard | GB/T 3091, GB/T 13912, BS 1387, ASTM A53, ASTM A500, ASTM A106, ASTM F1083, JIS, BIS, KS, API |
| Section Shape | Round |
| Size Range | Outer Diameter 10–1000 mm |
| Wall Thickness | 1–80 mm |
| Length | 1–12 m (standard 6 m / 6.4 m / 12 m, customizable) |
| Technique | ERW / Hot Rolled |
| Surface Treatment | Oiled / Non-oiled / Black (Hot Rolled) |
| Tolerance | ±1% |
| Ends | Plain / Beveled / Threaded (customizable) |
| Application | Fluid transport, hydraulic systems, structural pipe, machinery parts, construction |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| EPC Contractors | Chemical fertilizer pipelines, oil and gas fluid transport systems, industrial water supply networks |
| Construction Companies | Structural support columns, curtain wall frames, scaffolding tubes, fence posts |
| Machinery Manufacturers | Hydraulic cylinder bodies, conveyor system structural frames, equipment base supports |
| Infrastructure Developers | Greenhouse framing, bridge handrails, municipal drainage systems |
Where Wall-Thickness Tolerance Decides Whether Your Shipment Clears Inspection
A ±1% tolerance on a Q345 ERW welded steel pipe is not a marketing line — it is the difference between passing third-party inspection and paying demurrage at the port.
When structural engineers specify wall thickness for load-bearing frames or fluid conveyance systems, they calculate based on nominal dimensions. If the actual wall thickness drifts beyond acceptable deviation, the pipe fails ultrasonic testing or crush-load verification on site. I have seen entire container loads of ERW welded steel pipe held at destination ports because the mill did not control wall thinning during the forming and welding pass. The buyer then faces re-inspection costs, project delays, and in some cases, complete rejection of the shipment. [NEED_CITE: EN 10219 dimensional tolerance requirements for cold-formed welded hollow sections]
Matching Q235 and Q345 Grades to Structural and Fluid Transport Demands
The Q235 Q345 ERW welded steel pipe range covers outer diameters from 10 mm to 1000 mm, which means a single procurement order can supply both small-bore hydraulic lines and large-diameter structural columns. For greenhouse framing and fence post applications, Q195 or Q235B provides adequate yield performance at lower cost. When the project shifts to load-bearing columns or industrial conveyor structures, upgrading to Q345B or S355JR delivers the higher yield strength needed without changing the pipe geometry. Our production lines run all these grades on the same ERW equipment, so switching between structural and fluid transport specifications does not require separate sourcing from different mills.
Engineering Compliance and Surface Protection Across Corrosive Environments
Structural applications governed by EN 1993 or AISC design codes require documented material traceability and verified mechanical properties. The Q235/Q345 ERW welded steel pipe we produce meets GB/T 3091 and GB/T 13912 standards domestically, and equivalent grades such as S235JR, S275JR, and S355JR conform to EN 10219 for European projects, while A53 and A500 cover North American structural and fluid transport requirements. [NEED_CITE: steel grade equivalence mapping between GB, EN, and ASTM systems] For outdoor or marine-adjacent installations, the oiled surface treatment provides short-term transit corrosion protection, while non-oiled or black finish pipes can receive site-applied galvanizing or 3PE coating depending on the service environment. Beveled or threaded ends allow direct welding or mechanical coupling on site, reducing secondary fabrication time.
Understanding the ERW Process and Grade Selection for Welded Pipe
ERW (Electric Resistance Welding) forms the steel strip into a round profile and fuses the seam through localized electrical heating without filler metal. This process produces a consistent weld bead suitable for low-to-medium pressure fluid transport and structural applications up to 1000 mm outer diameter. Compared to seamless pipe, ERW offers lower production cost and tighter dimensional tolerance — the ±1% control on our lines ensures wall thickness uniformity across the full 1–80 mm range. Steel grade selection directly affects performance: Q195 and Q235B serve general structural and low-pressure water conveyance, while Q345B and 16Mn provide higher manganese content for improved weldability and toughness in load-bearing frames. The S-series grades (S235JR through S355JR) follow European naming conventions with guaranteed minimum yield strength at room temperature, and the ASTM A53/A500/A106 grades align with American specifications for structural and high-temperature service. [NEED_CITE: ERW versus seamless pipe application range comparison]
The Hidden Cost of Accepting Unverified Wall Thickness and Missing Mill Certificates
Purchasing ERW welded steel pipe without verified mill test certificates creates risk at multiple stages. At customs, officers in the EU and Middle East routinely hold steel shipments lacking CE documentation or EN 10219 compliance proof, triggering inspection delays that run into weeks. On site, if the wall thickness deviates beyond the specified tolerance, the engineer must either reject the material or redesign the structure — both options carry significant cost. [NEED_CITE: customs documentation requirements for steel pipe imports into EU markets] Material traceability through heat numbers ensures that every pipe in the bundle can be linked back to its original coil chemistry and rolling records, which is essential for project handover documentation and long-term asset maintenance.
Procurement Confidence Through Direct Factory Control and Verified Documentation
Every Q235 Q345 ERW welded steel pipe we ship comes from our own three production lines in Jinan, meaning you deal directly with the manufacturing source — no trading company markup, no third-party warehousing, and no information gaps between your specification and the mill floor. Our in-house physical and chemical laboratory tests every heat before the pipe leaves the facility, producing original mill test certificates that document chemical composition and mechanical properties against the applicable standard. We hold CE certification under EN 10210 and EN 10219, ISO 9001:2015 quality management registration, and accept SGS or BV third-party inspection at any stage of production. With over 2,800 specifications in our catalog and the ability to produce non-standard outer diameters, wall thicknesses, and cut-to-length requirements, we consolidate what would otherwise require multiple suppliers into a single procurement package. Our logistics team handles container loading optimization and coordinates FOB, CIF, or DDP delivery to ports across 50+ countries.
Documentation & Compliance
- Mill test certificate documenting Q235B or Q345B chemical composition and mechanical properties per GB/T 3091 or EN 10219 equivalent
- CE certificate confirming compliance with EN 10210 and EN 10219 for structural hollow sections exported to European markets
- ISO 9001:2015 quality management system certificate covering the full ERW welded pipe production process
- SGS or BV third-party inspection report available upon request, covering dimensional verification and surface quality
- Full material traceability by heat number linking each pipe to its original coil test records
- Export customs documentation including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- ERW welded round pipes bundled with steel strip ties and padded edge protectors to prevent surface damage during ocean transit
- Oiled surface treatment applied before bundling to provide corrosion protection throughout the shipping period
- Container loading plans optimized for 6 m and 12 m standard lengths to maximize payload per 20ft or 40ft container
- Cut-to-length service available for non-standard project requirements within the 1–12 m range
- Heat number and steel grade stenciled on each pipe bundle for site identification and traceability
- FOB, CIF, and DDP shipping terms available with door-to-door logistics coordination to destination ports
Start Your Procurement With Verified Specifications and Mill Documentation
Submit your required outer diameter, wall thickness, steel grade, quantity, and destination port to receive a detailed quotation including unit pricing, production lead time, and applicable certification documentation. We provide original mill test certificates and support SGS or BV third-party inspection before shipment, ensuring your Q235 Q345 ERW welded steel pipe order meets both engineering specifications and customs compliance requirements.
Frequently Asked Questions
Q: What is the difference between Q235B and Q345B for ERW welded steel pipe applications?
A: Q235B is a general-purpose carbon structural steel suitable for standard structural frames, fluid transport, and low-pressure applications. Q345B contains higher manganese content, providing improved yield strength and better weldability for load-bearing structures and heavier-duty industrial applications.
Q: Can you provide mill test certificates for European projects requiring EN 10219 compliance?
A: Yes. We issue original mill test certificates documenting chemical composition and mechanical properties, and our products hold CE certification under EN 10210 and EN 10219. We also accept SGS or BV third-party inspection for projects requiring independent verification.
Q: What is the minimum order quantity for custom outer diameter or wall thickness?
A: We maintain over 2,800 specifications across our production lines. For non-standard dimensions outside the catalog range, minimum order quantities depend on the specific size and steel grade requested. Contact us with your exact requirements for a tailored quotation.
Q: How do you ensure wall thickness tolerance during ERW production?
A: Our ERW production lines employ real-time ultrasonic thickness monitoring during the forming and welding process. Each heat is tested in our in-house laboratory before shipment, and the mill test certificate documents actual measured wall thickness against the specified tolerance of ±1%.
Q: What surface treatment options are available for corrosion protection?
A: Standard options include oiled finish for transit protection, non-oiled black finish for projects that will apply site coating, and we can arrange hot-dip galvanizing or 3PE anti-corrosion coating based on your project environment and specification requirements.
Request Your Q235 Q345 ERW Welded Steel Pipe Quotation Today
Send your specifications including outer diameter, wall thickness, steel grade, quantity, and destination port to receive pricing, production lead time, and mill test certificate documentation within 12 hours.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.sdxjysteel.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@sdxjysteel.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
