Description
Factory-Direct ERW Round Pipe — 3 dedicated production lines producing SS400 and S235JR welded circular steel pipe with in-house physical and chemical laboratory verification for every heat.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | SS400 / S235JR Welded Circular Steel Pipe |
| Product Type | Welded Circular Steel Pipe (ERW) |
| Steel Grade | SS400, S235JR, S235GR2, Q195, Q235A-B, Q345A-E, 20#, 10#, ASTM A53, ASTM A500, ASTM A106, St37, St52, S355TRH |
| Standard | GB/T 3091, ASTM A53, ASTM A500, ASTM A106, BS 1387, ASTM F1083 |
| Section Shape | Round |
| Size Range | Outer Diameter 10–1000 mm |
| Wall Thickness | 1–80 mm |
| Length | 1–12 m (or customized) |
| Technique | Hot Rolled / Welded (ERW) |
| Surface Treatment | Black Painting / Oiled / Non-oiled |
| Tolerance | ±1% |
| Ends | Plain / Beveled (per requirement) |
| Application | Fluid delivery (water, gas, pump well) / Structural pipe (greenhouse, fence post, curtain wall) / Construction pipe / Machinery parts |
| MOQ | 5 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| EPC Contractors | Water transmission pipelines, pump well casings, industrial fluid transport systems |
| Construction Companies | Building frames, scaffolding structures, curtain wall support systems, fence posts |
| Machinery Manufacturers | Conveyor system frames, hydraulic cylinder bodies, equipment support structures |
| Infrastructure Projects | Greenhouse frameworks, bridge handrails, sound barrier posts |
Where Dimensional Tolerance Decides Structural Fit-Out on a Welded Circular Steel Pipe Order
±1% tolerance on OD and wall thickness prevents field rework and connection failures.
When a structural frame requires dozens of welded joints, even minor deviations compound. A pipe running 2% under nominal wall thickness might pass visual inspection but fails ultrasonic testing at the weld prep stage. I have seen entire scaffold batches rejected at site because the contractor could not achieve consistent fit-up with couplers designed for standard EN 10219 dimensions [NEED_CITE: EN 10219 cold-formed hollow section dimensional tolerance requirements]. The cost is not just the rejected material — it is crane time idle, welders standing by, and schedule slippage that ripples through the critical path.
How SS400 and S235JR ERW Pipe Matches Structural and Fluid Applications
The SS400 S235JR welded circular steel pipe covers both load-bearing frames and low-pressure fluid lines because these grades balance formability with adequate yield strength for non-critical structural work. For greenhouse frames and fence posts, the oiled surface provides sufficient corrosion resistance during construction without the cost premium of galvanizing. When the same pipe spec moves into curtain wall support systems, the ±1% tolerance ensures bracket connections align without shimming. Our 3 production lines handle the full 10–1000 mm OD range in a single order, so EPC contractors sourcing both structural tubes and fluid lines avoid splitting procurement across multiple mills.
Engineering Compliance and Certification Requirements for ERW Round Pipe
Structural applications in the EU require CE marking under EN 10210 or EN 10219, and customs authorities routinely hold shipments lacking Factory Production Control documentation [NEED_CITE: CE marking requirements for structural hollow sections under EN 10210]. For North American projects, ASTM A53 and A500 compliance determines whether the pipe can be used in load-bearing frames or remains restricted to fencing. The S235JR grade specifies impact testing at 20°C, while S235GR2 extends this to 0°C — selecting the wrong sub-grade for cold-climate infrastructure creates latent fracture risk. Our in-house laboratory tests every heat for chemical composition and mechanical properties before release, and third-party inspection from SGS or BV is available for projects requiring independent verification.
Steel Grade Equivalence and ERW Process Fundamentals
SS400 (JIS), S235JR (EN), and Q235B (GB) occupy similar yield strength ranges and are often specified interchangeably in international tenders, but their chemical composition limits and impact testing requirements differ [NEED_CITE: steel grade equivalence between JIS SS400, EN S235JR, and GB Q235B]. ERW welding produces a longitudinal seam suitable for low to medium pressure applications, distinguishing it from seamless pipe for high-pressure service or SSAW for large-diameter water transmission. The hot-rolled process used for heavier wall sections (above 20 mm) ensures uniform grain structure through the thickness, while thinner walls benefit from the dimensional consistency of cold-formed ERW. Surface treatment selection — black painting for indoor structural use, oiled for temporary outdoor protection, or bare for subsequent galvanizing — depends on the corrosion environment and project timeline.
Hidden Costs of Specifying the Wrong Grade or Accepting Negative Tolerance Abuse
Material substitution without engineering approval — such as replacing S235JR with a lower-grade equivalent — compromises structural integrity and voids design certifications. Negative tolerance abuse, where wall thickness consistently runs at the lower limit, reduces load capacity and triggers rejection during third-party inspection [NEED_CITE: consequences of negative tolerance in structural steel procurement]. Missing or forged mill test certificates cause customs holds that delay projects by weeks, while inconsistent material properties across heats create unpredictable welding behavior. The true cost is never the unit price difference — it is the rework, the schedule delay, and the liability exposure when a structure fails to perform as designed.
Why Procurement Teams Source SS400 S235JR Welded Circular Steel Pipe From Our Mill
Factory-direct pricing eliminates trading company markups while maintaining full traceability from slab to finished pipe. Our 41 invention patents include proprietary welding parameters that ensure seam integrity across the full 1–80 mm wall thickness range. The in-house physical and chemical laboratory provides real-time process control, not just final inspection, catching deviations before they become non-conforming product. With 2,800+ specifications in our catalog, we consolidate structural tubes, fluid pipes, and section steel into single shipments, reducing coordination overhead for EPC contractors. CE certification under EN 10210/10219 and ISO 9001:2015 registration satisfy the most stringent project compliance requirements, while our export experience to 50+ countries means we understand the documentation and packaging standards each market demands.
Documentation & Compliance
- Mill Test Certificate documenting SS400 and S235JR chemical composition and mechanical properties per JIS G3101 and EN 10025
- CE certificate confirming compliance with EN 10210/EN 10219 for structural hollow sections in EU markets
- ISO 9001:2015 quality management system certificate covering the full ERW pipe production process
- SGS or BV third-party inspection report available for projects requiring independent material verification
- Heat number traceability linking each pipe to its original mill test certificate and chemical analysis
- Customs documentation package including packing list, Bill of Lading, and Certificate of Origin
Packaging, Loading & Delivery
- Black painted and oiled SS400 S235JR pipes bundled with steel strips and edge protectors to prevent surface damage during ocean transit
- Wall thickness above 20 mm shipped in loose bundles with wooden cradles to distribute weight and prevent ovalization
- Container loading optimized for 1–12 m lengths with maximum weight utilization for 20ft and 40ft containers
- Custom cut lengths available with plain or beveled ends per project specification, marked with heat number and steel grade
- FOB, CIF, and DDP shipping terms available with professional loading plans for ports across 50+ countries
- Seaworthy packaging with waterproof wrapping for oiled surfaces to prevent condensation damage during extended transit
How to Request a Quotation for Your ERW Round Pipe Requirement
Submit your specification sheet including outer diameter, wall thickness, steel grade, quantity, and destination port to receive a detailed quotation within 12 hours. We provide original mill test certificates and CE documentation with every shipment, and third-party inspection can be arranged before loading if your project requires independent verification. For non-standard sizes or custom lengths outside our 10–1000 mm OD range, our engineering team will confirm feasibility and lead time based on current production scheduling.
Frequently Asked Questions
Q: What is the difference between SS400, S235JR, and Q235B steel grades?
A: These grades occupy similar yield strength ranges but follow different regional standards — SS400 per JIS G3101 (Japan), S235JR per EN 10025 (Europe), and Q235B per GB/T 700 (China). S235JR specifies Charpy impact testing at 20°C, while SS400 and Q235B do not require impact testing as standard. For projects in cold climates or dynamic loading conditions, S235JR or S235GR2 (impact tested at 0°C) provides additional assurance.
Q: Can you provide mill test certificates for customs clearance?
A: Yes, every shipment includes original Mill Test Certificate (EN 10204 3.1 format) documenting chemical composition and mechanical properties for each heat number. For EU projects, we also provide CE certificate and Factory Production Control documentation required for customs clearance under EN 10210/EN 10219.
Q: What is the minimum order quantity for SS400 S235JR welded circular steel pipe?
A: The standard MOQ is 5 tons, which typically fills a 20ft container for smaller diameter pipes (10–200 mm OD) or represents a partial shipment for larger diameters. Trial orders for sample evaluation are accepted before committing to full production quantities.
Q: Do you offer custom lengths and end preparations?
A: Yes, we provide custom cutting to your specified lengths within the 1–12 m range, with plain ends for welding or beveled ends per your welding procedure specification. End preparation is included in the base price for standard bevel angles; special requirements are quoted separately.
Q: How do you ensure dimensional tolerance on wall thickness?
A: Our in-house physical laboratory conducts ultrasonic thickness testing at incoming, in-process, and final inspection stages. The ±1% tolerance is maintained through real-time process control on our 3 dedicated ERW production lines, and third-party inspection from SGS or BV can verify compliance before shipment.
Get Your SS400 S235JR Welded Circular Steel Pipe Quotation Today
Send your specification requirements to admin@sdxjysteel.com or contact us via WhatsApp at +86 188 5315 7756 to receive pricing, mill test certificate samples, and delivery timeline for your project.
