Description
Factory-Direct ERW Round Pipe Supply — Every Q235 Q355 S355JH ERW welded round steel pipe rolls off our own ERW lines, bypassing trading markups while maintaining ±1% wall-thickness tolerance verified by our in-house lab.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235 Q355 S355JH ERW Welded Round Steel Pipe |
| Product Type | ERW Welded Round Steel Pipe |
| Steel Grade | Q195, Q235, Q355, SS400, S355JH, 10#, 20#, 45#, 16Mn, ASTM A53, ASTM A106, ASTM A252, ASTM A500, ST35, ST52 |
| Standard | API 5L, ASTM A53, ASTM A106, ASTM A252, ASTM A500, ASTM A671, ASME B36.10M, BS EN 10219, BS EN 10296, BS 1387, BS 6323, BS 6363, 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, Galvanized (Zinc Coated 200–700 g/m²) |
| Tolerance | ±1% |
| Ends | Plain / Beveled (available upon request) |
| Application | Fluid transport, structural frames, construction, boiler systems, scaffolding, machinery, fencing, greenhouse structures |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Infrastructure | Structural columns, pile foundations, scaffolding tubes, bridge support frames |
| Fluid Transport | Municipal water pipelines, oil and gas distribution lines, industrial process piping |
| Machinery & Industrial Equipment | Hydraulic cylinder barrels, equipment frames, conveyor support structures |
| Agricultural & Greenhouse | Greenhouse framing, irrigation systems, fencing posts |
What Wall-Thickness Tolerance Costs on a Structural Frame Order
A ±1% tolerance on a Q235 Q355 S355JH ERW welded round steel pipe is the difference between passing on-site inspection and scrapping an entire container.
Procurement teams ordering ERW round pipes routinely face three compounding failures: wall thickness drifting beyond acceptable negative tolerance triggers rejection during structural acceptance checks; missing or inconsistent mill test certificates stall customs clearance at destination ports; and grade mismatches between Q-series, S-series, and ASTM designations cause material substitution errors that compromise load-bearing calculations [NEED_CITE: EN 10219 cold-formed hollow section dimensional tolerance requirements]. Each failure multiplies cost through re-inspection fees, project delays, and potential structural rework.
Matching OD and Wall Thickness to Structural Load Requirements
Selecting the correct Q235 Q355 S355JH ERW welded round steel pipe starts with aligning outer diameter and wall thickness to the structural load path. Cold-rolled pipes in the 1–4.0 mm wall range serve precision machinery frames and greenhouse structures where dimensional accuracy matters more than raw load capacity. Hot-rolled pipes from 4–20 mm wall thickness carry structural columns, pile foundations, and scaffolding systems that demand higher section modulus. Our ERW lines produce both ranges on dedicated equipment, with wall thickness held within ±1% tolerance verified by ultrasonic measurement before shipment.
Engineering Compliance Across International Standards
Structural engineers specifying Q355 or S355JH need assurance that the pipe conforms to the governing design code. EN 10219 governs cold-formed welded structural hollow sections in European projects, while ASTM A500 and A53 dominate North American structural and fluid transport applications. API 5L and GB/T 9711 cover pipeline systems for oil and gas. Our Q235 Q355 S355JH ERW welded round steel pipe carries CE certification under EN 10210/EN 10219 for EU market access, with full chemical composition and mechanical property documentation aligned to each standard framework [NEED_CITE: steel grade equivalence mapping between GB Q-series and EN S-series].
Decoding Steel Grade Selection for ERW Round Pipe
The Q-series (Q195, Q235, Q355) follows the Chinese GB system where the number indicates minimum yield strength in MPa. The S-series (S355JH) follows EN standards with equivalent yield levels but different impact testing requirements — the “JH” suffix denotes impact testing at elevated temperatures for structural applications. ASTM A53 and A500 serve North American markets with Grade B and Grade C designations respectively. SS400 and ST35/ST52 represent JIS and DIN legacy grades still specified in older projects. Our cross-reference documentation eliminates ordering errors when projects require grade substitution between systems [NEED_CITE: international steel grade equivalence tables for structural hollow sections].
ERW welding joins the edges of a rolled steel strip through high-frequency electrical resistance, creating a longitudinal weld seam. This process suits outer diameters from 10–700 mm with consistent wall thickness, offering cost advantages over seamless pipe for structural and low-to-medium pressure fluid transport. Hot-dip galvanizing with 200–700 g/m² zinc coating extends service life in corrosive environments, while oiled or bare black finishes serve indoor or temporary applications.
The Hidden Cost of Negative Tolerance and Missing Certification
Ordering Q235 Q355 S355JH ERW welded round steel pipe based on price alone invites three hidden costs: wall thickness below specified tolerance reduces section modulus and triggers structural rejection; absent or forged mill test certificates block customs clearance and delay project timelines; and grade mislabeling — such as supplying Q235 when Q355 is specified — creates latent structural safety risks that surface only during load testing or service failure [NEED_CITE: consequences of dimensional non-compliance in structural steel procurement]. Third-party inspection by SGS or BV before shipment, combined with heat-number traceability, eliminates these risks.
Why Project Procurement Teams Source ERW Round Pipe From Us
Our dedicated ERW production lines cover outer diameters from 10–700 mm and wall thickness from 1–20 mm, eliminating the need to split orders across multiple suppliers. Every Q235 Q355 S355JH ERW welded round steel pipe passes through our in-house physical and chemical laboratory for dimensional verification, mechanical testing, and chemical composition analysis before shipment. CE certification under EN 10210/EN 10219 ensures EU market compliance, while ISO 9001:2015 quality management and SGS/BV third-party verification satisfy international procurement requirements. Custom non-standard sizes, beveled ends, and specific length cutting are available with MOQ of just 1 Ton. Professional container loading with anti-damage measures prevents bending and surface damage during ocean transit, a critical factor for galvanized pipes where zinc coating integrity matters.
Documentation & Compliance
- Mill test certificate documenting Q235, Q355, or S355JH chemical composition and yield strength per EN 10219 or ASTM A500
- CE certificate under EN 10210/EN 10219 for structural hollow sections exported to EU markets
- ISO 9001:2015 quality management system certificate covering ERW pipe production processes
- SGS or BV third-party inspection report verifying dimensional tolerance and surface treatment quality
- Material traceability by heat number linking each pipe to its mill test certificate
- Complete customs documentation including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- ERW round pipes bundled with steel strips and edge protectors to maintain ±1% dimensional tolerance during ocean transit
- Galvanized Q235 Q355 S355JH ERW welded round steel pipe wrapped with moisture-resistant material to preserve zinc coating (200–700 g/m²)
- Container loading optimized for 1–12 m lengths with anti-bending supports to prevent deformation of thin-wall cold-rolled pipes (1–4.0 mm)
- Heat number and steel grade stenciled on each pipe for on-site traceability and inspection verification
- FOB, CIF, and DDP shipping terms available with professional export documentation
- Custom cutting to specific lengths available for scaffolding and structural frame applications
Request Quotation With Mill Test Certificate
Submit your Q235 Q355 S355JH ERW welded round steel pipe specifications — including outer diameter, wall thickness, steel grade, surface treatment, quantity, and destination port — to receive a detailed quotation with unit price, production lead time, and shipping terms within 12 hours. Mill test certificates and third-party inspection arrangements are confirmed before contract signing.
Frequently Asked Questions
Q: How do Q235, Q355, S355JH, and ASTM A53 compare for structural applications?
A: Q235 and Q355 follow Chinese GB standards with minimum yield strengths of 235 MPa and 355 MPa respectively. S355JH follows EN 10219 with equivalent yield strength to Q355 but includes impact testing at elevated temperatures for structural applications. ASTM A53 Grade B serves North American markets with similar mechanical properties. We provide cross-reference documentation to ensure correct grade selection for your project specifications.
Q: Can you provide mill test certificates and arrange third-party inspection?
A: Yes. Every Q235 Q355 S355JH ERW welded round steel pipe ships with a mill test certificate documenting chemical composition and mechanical properties per the specified standard. Third-party inspection by SGS or BV is available upon request before shipment to verify dimensional tolerance, surface treatment quality, and welding integrity.
Q: Do you produce non-standard outer diameters or wall thickness?
A: Yes. Our ERW production lines cover outer diameters from 10–700 mm and wall thickness from 1–20 mm (cold rolled 1–4.0 mm, hot rolled 4–20 mm). Custom non-standard sizes outside these ranges are available with MOQ of 1 Ton. Specific length cutting from 1–12 m and beveled ends are also available.
Q: When should I choose hot-dip galvanized versus oiled or black pipe?
A: Hot-dip galvanized Q235 Q355 S355JH ERW welded round steel pipe with 200–700 g/m² zinc coating suits outdoor, marine, or corrosive environments where long-term corrosion resistance is critical. Oiled pipes serve indoor applications or temporary structures where short-term rust prevention is sufficient. Bare black pipes are specified for indoor structural frames, machinery, or applications where surface treatment will be applied on-site.
Q: What export documentation do you provide for customs clearance?
A: We provide complete export documentation including mill test certificates, CE certificate (EN 10210/EN 10219) for EU markets, ISO 9001:2015 certificate, packing list, bill of lading, and certificate of origin. Material traceability by heat number links each pipe to its test certificate. Third-party inspection reports from SGS or BV are available upon request.
Get Your Q235 Q355 S355JH ERW Welded Round Steel Pipe Quote Today
Send your specifications to admin@sdxjypipe.com or contact us via WhatsApp at +86 188 5315 7756 to receive a detailed quotation with mill test certificate within 12 hours.
