Description
Factory-Direct ERW Round Pipe — In-house lab verification on every heat before MTC release
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235 Q355 S355JH ERW Round Steel Pipe |
| Product Type | ERW Welded Round Steel Pipe |
| Steel Grade | Q195, Q235, Q345, Q355, S355JH, SS400, 10#, 20#, 45#, 16Mn, ASTM A53, ASTM A500, ST35, ST52 |
| Standard | API 5L, ASTM A53, ASTM A106, ASTM A252, ASTM A523, ASTM A671, ASME B36.10M, BS 1387, BS EN 10219, BS EN 10296, BS 6323, GB/T 3091, GB/T 13793, GB/T 9711, JIS G3466 |
| Section Shape | Round |
| Size Range | Outer Diameter 10–700 mm |
| Wall Thickness | Cold rolled 1–4.0 mm / Hot rolled 4–20 mm |
| Length | 1–12 m |
| Technique | ERW (Hot Rolled / Cold Rolled) |
| Surface Treatment | Hot Rolled, Oiled, Zinc Coated (200–700 g/m²) |
| Tolerance | ±1% |
| Ends | Plain / Beveled |
| Application | Fluid transport, structural frames, scaffolding, boiler pipe, hydraulic pipe, machinery parts |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| EPC Contractors & Construction | Structural columns, roof trusses, scaffolding uprights, fluid and gas distribution pipelines |
| Machinery Manufacturers | Hydraulic cylinder barrels, drill pipe casings, conveyor roller shafts |
| Industrial Distributors | Regional stock of ERW round pipes for redistribution across EN, ASTM, and GB grade requirements |
What Missing Mill Test Certificates Cost on a Q355 Pipe Order
An unverified MTC can lock two containers at port for weeks while re-inspection bills accumulate.
Global buyers ordering Q235 Q355 S355JH ERW welded round steel pipe frequently encounter three compounding problems: material chemistry that drifts from the mill cert, certificates missing heat-number traceability, and fragmented sourcing that forces coordination across multiple vendors for pipes, plates, and fabrication. On thin-wall ERW rounds — say 48×2.0 mm — tolerance margins are tight enough that a manganese deviation invisible on paper becomes a weld-seam failure under load. [NEED_CITE: EN 10219 cold-formed hollow section chemical composition requirements]
Matching ERW Round Pipe to Structural and Fluid Applications
The OD 10–700 mm range covers everything from small-bore hydraulic lines to large-diameter structural columns, while the cold-rolled 1–4 mm and hot-rolled 4–20 mm wall bands separate precision machinery applications from heavy construction use. For EPC projects requiring Q355 or S355JH structural frames, the ±1% tolerance and beveled ends support direct butt-weld preparation on site. Our in-house physical and chemical laboratory tests every heat against the declared grade before the Q235 Q355 S355JH ERW welded round steel pipe leaves the mill — the same cross-check process that prevents the port-side re-testing failures I have seen firsthand.
Engineering Compliance Across EN, ASTM, and GB Standards
Structural applications in the EU require CE marking under EN 10210 or EN 10219, while North American projects specify ASTM A53 or ASTM A500 — and customs authorities on both sides increasingly reject shipments where the certificate standard does not match the purchase order. The Q235 Q355 S355JH ERW welded round steel pipe we produce covers all three systems from a single production run, with mill test certificates referencing the exact standard called in the contract. For corrosive environments, hot-dip galvanizing at 200–700 g/m² zinc coating extends service life without sacrificing the dimensional tolerance required for bolted or welded connections. [NEED_CITE: steel grade equivalence between EN 10219 and ASTM A500 standards]
Steel Grade Selection and ERW Weld Integrity
Q235 and Q355 represent the Chinese GB system where the number indicates minimum yield strength in MPa; S355JH is the European EN equivalent with impact testing at sub-zero temperatures; ASTM A53 and A500 serve the same structural roles in North American specifications. The ERW process creates a longitudinal weld seam that, when properly controlled through in-process ultrasonic inspection and post-weld heat treatment, delivers strength comparable to the parent metal — critical for pressure-rated fluid transport and load-bearing columns alike. Surface treatment choice follows the environment: oiled hot-rolled pipe suits indoor structural use, while zinc-coated ERW rounds handle outdoor scaffolding and coastal infrastructure where corrosion resistance outweighs initial cost. Wall thickness tolerance at ±1% means theoretical weight calculations stay reliable for shipping and structural load planning. [NEED_CITE: ERW weld seam quality control methods per API 5L and EN 10219]
The Hidden Cost of Wrong Grade or Missing Certification
Specifying Q235 when the structural engineer calculated for Q355 does not show up until the building frame fails load inspection — at which point every pipe on site must be replaced, not just the non-conforming batch. Missing CE documentation halts EU customs clearance for weeks; absent heat-number traceability voids third-party inspection reports and forces costly re-testing. With the Q235 Q355 S355JH ERW welded round steel pipe, every shipment carries original mill test certificates cross-referenced to our in-house lab results, so the chemistry on paper matches the chemistry in the pipe. [NEED_CITE: consequences of material certification gaps in international steel trade]
Why Procurement Teams Source This Pipe From Us
We run three dedicated ERW production lines with in-house physical and chemical laboratories, meaning every Q235 Q355 S355JH ERW welded round steel pipe is tested before the MTC is signed — not sampled after the fact. The factory-direct model eliminates trading company markups while covering 2,800+ specifications across round, square, rectangular, and section steel from a single purchase order. Our CE certification under EN 10210 and EN 10219, ISO 9001:2015 registration, and acceptance of SGS or BV third-party inspection before shipment address the certification gaps that cause the most frequent customs delays. Custom non-standard sizes,定尺 cutting, and professional container loading plans handle the logistics complexity that fragments multi-supplier orders. Exports to 50+ countries across the EU, North America, Middle East, and Southeast Asia mean we have already navigated the documentation requirements for your destination port.
Documentation & Compliance
- Mill test certificate documenting Q235, Q355, or S355JH chemical composition and mechanical properties per GB/T 9711, EN 10219, or ASTM A53 as specified
- CE certificate under EN 10210 / EN 10219 for structural hollow sections entering EU member states
- ISO 9001:2015 quality management certificate covering the full ERW production and inspection process
- SGS or BV third-party inspection report available upon request before container sealing
- Full heat-number traceability from raw coil to finished pipe, referenced on every length marking
- Customs document package including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- ERW round pipes bundled with steel strips and edge protectors, sized to match the 1–12 m length range for stable ocean transit
- Oiled surface treatment applied before bundling to prevent rust during container shipping; galvanized pipes receive additional plastic end caps to preserve the zinc coating
- Container loading plans optimized for OD 10–700 mm diameter ranges, nesting small-bore pipes inside larger diameters to maximize 20ft and 40ft container utilization
- Cut-to-length service available for 1–12 m定尺 requirements, with each piece marked by heat number, steel grade, and size
- FOB, CIF, and DDP shipping terms with door-to-door logistics coordination to 50+ countries
Start Your Procurement With Verified Specifications
Submit your required outer diameter, wall thickness, steel grade, quantity, and destination port — we return a detailed quotation including unit price, delivery timeline, applicable certifications, and mill test certificate format within 12 hours. For non-standard sizes outside the 10–700 mm OD or 1–20 mm wall range, our engineering team reviews feasibility and provides a custom production plan.
Request Your Quotation and Mill Test Certificate
Email: admin@sdxjysteel.com
WhatsApp: +86 188 5315 7756
Website: www.sdxjysteel.com
Frequently Asked Questions
Q: How do Q235, Q355, and S355JH steel grades compare across different standards?
A: Q235 and Q355 follow the Chinese GB system where the number indicates minimum yield strength in MPa. S355JH is the European EN equivalent with Charpy impact testing requirements at sub-zero temperatures. ASTM A53 and A500 serve similar structural roles in North American specifications. We provide cross-reference documentation and produce to whichever standard your project requires.
Q: What mill test certificate documents are included with each shipment?
A: Every shipment includes an original mill test certificate showing chemical composition and mechanical properties for the specific heat number. The MTC references the applicable standard (GB/T 9711, EN 10219, ASTM A53, etc.) and is cross-checked against our in-house laboratory results before release.
Q: Can you produce ERW round pipes with non-standard outer diameter or wall thickness?
A: Yes. Our standard range covers OD 10–700 mm with cold-rolled wall 1–4 mm and hot-rolled wall 4–20 mm. For sizes outside this range, we review your drawing or specification and provide a custom production plan with MOQ and lead time.
Q: When should I specify hot-dip galvanized versus oiled surface treatment?
A: Hot-dip galvanizing at 200–700 g/m² zinc coating suits outdoor, coastal, or corrosive environments where long-term rust protection is critical. Oiled surface treatment is sufficient for indoor structural applications or pipes that will receive field coating after installation. We can also apply custom coatings per project specification.
Q: What shipping terms and logistics support do you provide?
A: We offer FOB, CIF, and DDP terms with professional container loading plans that optimize space for round pipe diameters. Real-time tracking is available, and we coordinate door-to-door delivery to ports and project sites across 50+ countries.
Get Factory-Direct Pricing on Q235 Q355 S355JH ERW Welded Round Steel Pipe
Send your specifications, steel grade, quantity, and destination port to receive a detailed quotation with mill test certificate format and delivery timeline within 12 hours.
Email: admin@sdxjysteel.com
WhatsApp: +86 188 5315 7756
Website: www.sdxjysteel.com
