Description
Factory-direct ERW pipe supply — In-house physical and chemical laboratory testing every Q235 ERW round steel pipe before dispatch, with full mill test certificates provided per shipment.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235 ERW Round Steel Pipe |
| Product Type | ERW Round Steel Pipe |
| Steel Grade | Q195, Q235, Q345, S235JR, S275JR, S355JR, ASTM A53, ASTM A106, ASTM A500, SS400, St37, St52, 20#, 10#, 16Mn |
| Standard | GB/T 3091-2001, GB/T 13912-2002, BS 1387, ASTM F1083, ASTM A53, ASTM A106, ASTM A500 |
| Section Shape | Round |
| Size Range | Outer Diameter 10–1000 mm |
| Wall Thickness | 1–80 mm |
| Length | 1–12 m (customizable) |
| Technique | ERW / Hot Rolled |
| Surface Treatment | Oiled / Non-oiled / Consumer’s Requirement |
| Tolerance | ±1% |
| Ends | Plain / Beveled / Threaded |
| Application | Fluid delivery, chemical fertilizer pipeline, oil pipeline, hydraulic pipeline, drill pipe, boiler pipe, construction pipe, structural pipe, curtain wall, machinery parts |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Oil & Gas | Pump well tubing, gas distribution lines, oil pipeline systems |
| Chemical & Fertilizer | Chemical fertilizer pipeline, process fluid delivery, boiler feed lines |
| Construction & Infrastructure | Structural frames, curtain wall supports, greenhouse structures, fence posts |
| Machinery & Hydraulic | Hydraulic cylinder bore, machinery parts, precision-bore round pipe |
| Water & Municipal | Water supply networks, drainage systems, irrigation pipelines |
Why Mixed GB-ASTM-EN Orders Fail Without a Single Q235 ERW Round Steel Pipe Manufacturer
Grade equivalence confusion is the most common cause of material rejection at destination customs.
When a project specifies Q235 in the drawing but the procurement team orders ASTM A36 without confirming equivalence, the mill test certificate shows a different chemical composition range. Customs officers in the EU or Middle East flag the mismatch. The container sits at port. Demurrage accumulates. Someone has to fly out with replacement paperwork — or worse, replacement steel. [NEED_CITE: steel grade equivalence between EN and ASTM standards]
Sourcing from multiple suppliers for different grades compounds the problem. One batch arrives with S235JR certificates, another with Q235B test reports, and nobody on site can verify whether the wall thickness tolerance meets the structural engineer’s specification. The Q235 ERW round steel pipe manufacturer who consolidates all grades under one quality system eliminates this gap entirely.
Matching OD and Wall Thickness to Structural Load Requirements
Every project has a load calculation that determines the minimum wall thickness for a given outer diameter. A greenhouse structure using Q235 ERW round steel pipe at OD 48 mm with 2.0 mm wall thickness serves a completely different purpose than a hydraulic system requiring 80 mm wall at OD 200 mm. The ±1% dimensional tolerance on our ERW lines ensures that the actual bore matches the design calculation — critical when pressure rating depends on wall integrity. We produce the full OD 10–1000 mm range with wall thickness from 1 mm to 80 mm on three dedicated production lines, so engineers do not need to compromise on specification.
Engineering Compliance and Certification Pathways
Structural applications in the EU require CE marking under EN 10210 or EN 10219, and customs authorities increasingly reject shipments lacking proper factory production control documentation. [NEED_CITE: EN 10219 cold-formed hollow section requirements] For North American projects, ASTM A53 and A500 compliance with proper mill test certificates is non-negotiable. Our Q235 ERW round steel pipe carries Lloyd’s CE certification for EN 10210/10219, Singapore FPC approval, and full ISO 9001:2015 quality management coverage. Third-party inspection by SGS or BV is arranged before loading upon request. For projects requiring custom lengths beyond standard 6 m or 12 m, we cut to exact dimension and mark heat numbers on every piece for full traceability.
Understanding Steel Grade Selection for ERW Round Pipe
The Q-series (Q195, Q235, Q345) follows the Chinese GB standard system where the number indicates minimum yield strength in MPa. The S-series (S235JR, S275JR, S355JR) follows the European EN system with similar yield strength designation but different impact testing requirements — the JR suffix indicates room-temperature Charpy impact testing. ASTM A53 covers general pressure and mechanical applications, while ASTM A106 is specifically designed for high-temperature service. The ERW welding process produces a longitudinal weld seam that is suitable for low-to-medium pressure applications and structural use, offering cost advantages over seamless pipe at larger diameters. Surface treatment selection depends on the environment: oiled finish provides short-term rust prevention during transit and storage, while non-oiled or bare pipe is specified when the project applies its own coating system on site. [NEED_CITE: difference between ERW and seamless steel pipe applications]
The Hidden Cost of Tolerance Deviation and Missing Certificates
When wall thickness falls below the specified tolerance — even by a fraction of a millimeter — the structural engineer’s load calculation becomes invalid. A Q235 ERW round steel pipe ordered at 5.0 mm wall that arrives at 4.6 mm may pass visual inspection but fails ultrasonic testing at the project site. The entire batch must be rejected or downgraded. Missing or incorrect mill test certificates trigger customs holds that cost thousands in demurrage. Material without heat number traceability cannot be verified against the original chemical composition, making it impossible to confirm grade compliance. These are not theoretical risks — they are the daily reality for buyers who source from traders rather than certified manufacturers. [NEED_CITE: importance of mill test certificate in steel procurement]
Why Buyers Choose SD XJY Pipe for Q235 ERW Round Steel Pipe
We operate three dedicated ERW production lines covering over 2,800 specifications, meaning your non-standard diameter or heavy-wall requirement does not require sourcing from a second supplier. Our in-house physical and chemical laboratory performs dimensional measurement, mechanical testing, and chemical composition analysis on every production batch — the mill test certificate you receive is generated from actual test data, not template documents. As the original inventor of sharp-corner rectangular tube technology in China with 41 invention patents, we understand precision manufacturing at the micron level. Full international certifications including ISO 9001:2015, Lloyd’s CE, Singapore FPC, and SGS/BV verification ensure your shipment clears customs in any destination country. We have exported to over 50 countries across the EU, North America, Middle East, and Southeast Asia, with professional container loading protocols that prevent end deformation and surface damage during ocean transit.
Documentation & Compliance
- Mill test certificate documenting Q235 chemical composition and mechanical properties per GB/T 3091-2001, with heat number traceability
- CE certificate under EN 10210/EN 10219 for S235JR–S355JR grades exported to EU member states
- ISO 9001:2015 quality management system certificate covering the full ERW round pipe production process
- SGS or BV third-party inspection report available before container loading for projects requiring independent verification
- Material traceability documentation linking each pipe to its heat number, chemical composition report, and dimensional test results
- Complete customs documents including packing list, bill of lading, and certificate of origin for smooth destination clearance
Packaging, Loading & Delivery
- Q235 ERW round steel pipe bundled with steel strips and edge protectors to maintain ±1% tolerance during ocean transit
- Oiled surface treatment applied uniformly to prevent rust formation on bare pipe ends and weld seams during storage and shipping
- Container loading optimized by outer diameter grouping — small-bore pipe (OD 10–100 mm) nested inside large-diameter pipe (OD 500–1000 mm) to maximize 20ft and 40ft container utilization
- Custom length cutting from 1 m to 12 m per project specification, with each piece marked with steel grade, heat number, and length
- Shipping terms available as FOB, CIF, or DDP with professional loading supervision to prevent end deformation and bending damage
How to Request a Quotation for Q235 ERW Round Steel Pipe
Send your specification sheet including outer diameter, wall thickness, steel grade, quantity, length requirement, and destination port. We respond within 12 hours with a detailed quotation covering unit price, minimum order quantity, production lead time, and shipping terms. Mill test certificates and product samples are available for quality confirmation before contract signing.
Frequently Asked Questions
Q: What is the difference between Q235 and S235JR for ERW round pipe?
A: Both grades have similar minimum yield strength, but S235JR follows the European EN standard system and requires Charpy impact testing at room temperature (indicated by the JR suffix). Q235 follows the Chinese GB standard. For projects in the EU, S235JR with CE certification under EN 10219 is typically required. We provide grade equivalence cross-reference support to ensure correct specification.
Q: Can you provide third-party inspection before shipment?
A: Yes. SGS and BV third-party inspection is arranged upon request. The inspection covers dimensional verification, visual examination, weld seam quality, and review of mill test certificates. The inspection report is provided before container loading to confirm compliance with your purchase order.
Q: What is the minimum order quantity for custom non-standard sizes?
A: The MOQ is 1 Ton for standard specifications. For custom non-standard outer diameter, wall thickness, or length requirements, we evaluate feasibility based on our production line capabilities covering over 2,800 specifications. Contact us with your specific dimensions for confirmation.
Q: How do you ensure wall thickness tolerance of ±1%?
A: Our in-house physical and chemical laboratory performs dimensional testing on every production batch using calibrated measurement equipment. Each Q235 ERW round steel pipe is checked for outer diameter, wall thickness, and ovality before release. The mill test certificate documents actual measured values against the specified tolerance.
Q: What surface treatment options are available?
A: We offer oiled surface treatment for short-term rust prevention during transit and storage, non-oiled (bare) finish for projects that apply their own coating system, and custom surface treatment per your specification. Galvanized coating is also available upon request for corrosion-resistant applications.
Get Your Q235 ERW Round Steel Pipe Quote with Mill Test Certificate
Submit your specification including OD, wall thickness, grade, and quantity to receive a detailed quotation within 12 hours.
Company: Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.sdxjypipe.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@sdxjypipe.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
