Description
Factory-direct ERW round pipe supply — We roll, cut, and ship Q235 S355 ERW welded carbon steel round pipe from our own Shandong mill floor to your project site, eliminating broker markups and certificate gaps.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235 S355 ERW Welded Carbon Steel Round Pipe |
| Product Type | ERW Welded Steel Pipe (Round) |
| Steel Grade | Q195, Q235, Q355, 10#, 20#, 45#, 16Mn, A36, A53, A369, ST35, ST52, Grade A, Grade B, Grade C |
| Standard | API 5L, ASTM A53, ASTM A671, ASTM A252, ASTM A450, ASME B36.10M, ASTM A523, BS 1387, BS EN 10296, BS 6323, BS 6363, BS EN 10219, GB/T 3091, GB/T 13793, GB/T 9711 |
| Section Shape | Round |
| Size Range | Outer Diameter 32 mm – 1219 mm |
| Wall Thickness | Cold rolled 1 – 4.0 mm; Hot rolled 4 – 20 mm |
| Length | 1 – 12 m |
| Technique | ERW / Hot Rolled / Cold Rolled / Cold Drawn |
| Surface Treatment | Hot Rolled, Slightly Oiled |
| Tolerance | ±1% |
| Ends | Plain |
| Application | Fluid transport, boiler pipe, drill pipe, hydraulic pipe, chemical fertilizer pipe, building industry, machinery, structural frames |
| MOQ | 5 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Oil & Gas EPC | Flow lines, water injection piping, gas gathering headers per API 5L and ASTM A53 |
| Construction & Infrastructure | Building frames, scaffolding uprights, conveyor structures, bridge handrails |
| Machinery & Equipment | Hydraulic cylinders, roller frames, crane booms, agricultural machinery chassis |
| Power & Boiler | Boiler tubes, heat exchanger piping, pressure vessel nozzles per ASTM A450 and ASME B36.10M |
| Municipal & Water | Potable water mains, drainage culverts, irrigation pipelines |
What Missing Mill Certificates Cost on a Q235 S355 ERW Welded Carbon Steel Round Pipe Order
A pipe without traceable chemistry is scrap the moment customs or the site inspector asks for the heat number.
Buyers sourcing Q235 S355 ERW welded carbon steel round pipe from mixed supply chains routinely hit three walls: grade equivalence confusion between GB Q235, EN S235JR and ASTM A36; certificates that cannot be cross-checked against the heat number stamped on the pipe; and wall-thickness deviations that only surface after cutting begins. [NEED_CITE: steel grade equivalence between GB, EN and ASTM standards] When a structural frame fails acceptance because the mill test certificate lists a different heat batch than the pipe delivered, the entire lot gets quarantined — and the project timeline absorbs the delay, not the supplier.
Matching Wall Thickness and Grade to Structural and Fluid Service
A Q235 S355 ERW welded carbon steel round pipe selected for a building frame needs different thickness discipline than the same OD pipe running water on a municipal main. Structural members rely on consistent wall thickness to meet deflection limits under load, while fluid-service pipes prioritize internal surface condition and weld-seam integrity to resist corrosion and leakage over decades. We match the cold-rolled 1–4 mm wall range to light structural and furniture frames where weight matters, and the hot-rolled 4–20 mm wall range to pressure-containing and heavy-load applications — always pairing the correct grade (Q235 for general structures, Q355 or 16Mn for higher load paths, A53 for fluid code work) with the end-use standard the inspector will demand.
Engineering Codes, Corrosion Environments and Certification Paths
Structural engineers specifying round pipe for frames and bracing typically reference EN 1993 or AISC guidelines, which require documented yield strength and traceable chemistry — not just a grade stamp. [NEED_CITE: EN 10219 cold-formed and welded hollow section requirements] For outdoor or coastal installations, the slight-oil surface treatment on hot-rolled Q235 S355 ERW welded carbon steel round pipe offers transit protection but must be upgraded to galvanizing or 3PE coating before long-term exposure. Customs clearance into the EU demands CE documentation aligned with EN 10219, while North American projects require ASTM A53 or API 5L test reports; mixing these up at the port means demurrage, not a phone call.
Reading the Grade, the Process and the Tolerance
The Q-series (Q195, Q235, Q355) follows the Chinese yield-strength naming convention, where the number after “Q” indicates the minimum yield value in MPa — Q355 carries roughly 50% more load capacity than Q235, making it the default for crane booms and heavy bracing. The S-series (S235, S275, S355) and ASTM grades (A36, A53) follow parallel logic under EN and ASME frameworks, and equivalence tables let procurement swap one for another when supply tightens — provided the chemical composition and elongation actually match. [NEED_CITE: structural steel grade equivalence tables between EN 10025 and ASTM A36] ERW welding joins the edges of a hot-rolled coil under pressure and electrical current, producing a continuous longitudinal seam that is cost-effective for ODs up to 1219 mm and walls up to 20 mm; for higher-pressure steam or sour-service lines, seamless or SSAW processes take over. The ±1% tolerance on this Q235 S355 ERW welded carbon steel round pipe means a 10 mm wall can measure 9.9–10.1 mm — tight enough for structural calculation, but buyers must confirm whether the mill quotes theoretical or actual weight, because negative-tolerance practices quietly reduce load capacity.
The Hidden Price of Buying the Wrong Grade or the Wrong Certificate
Ordering A36 when the drawing calls for S355, or accepting a mill test certificate that does not match the heat number on the pipe, does not show up until the third-party inspector or the site welder catches it. [NEED_CITE: consequences of non-conforming steel in structural and pressure applications] The cost is never the pipe price — it is the cut-and-weld labor already spent, the crane time waiting for replacement material, and the engineering re-approval cycle. For pressure-rated work under ASTM A450 or API 5L, a missing or forged certificate turns a routine delivery into a rejected shipment, and the buyer carries the freight bill both ways.
Why Project Buyers Source This Q235 S355 ERW Welded Carbon Steel Round Pipe From Us
We operate the XJY Plate division out of our own Shandong facility, which means the Q235 S355 ERW welded carbon steel round pipe you order is rolled, inspected and loaded under one roof — no trading-company markup and no certificate hand-offs between unrelated parties. Every bundle ships with an original mill test certificate listing the heat number, chemical composition and mechanical properties, and we welcome SGS or BV third-party inspection before the container is sealed. Our in-house processing line handles custom cutting, punching, bending and slight oiling, so a 5-ton MOQ can arrive as 6-meter structural lengths ready to weld, not 12-meter randoms your yard has to re-cut. We have loaded flatbeds, open-top containers and break-bulk vessels for ODs up to 1219 mm, and the loading plan is checked against port weight limits before the crane hooks the first bundle — a lesson learned the hard way on a南美 shipment years ago. ISO 9001:2015 and CE certifications sit alongside our mill documentation, and our logistics team plans the entire route FOB, CIF or DDP, so the pipe arrives with the paperwork the destination customs officer expects.
Documentation & Compliance
- Mill test certificate documenting Q235 or S355 chemical composition, yield strength and elongation per GB/T 700 or EN 10025, cross-referenced to the heat number stamped on each pipe
- CE certificate confirming compliance with EN 10219 for welded structural hollow sections shipped to EU member states
- ISO 9001:2015 quality management certificate covering the rolling, welding and inspection process of the Q235 S355 ERW welded carbon steel round pipe
- SGS or BV third-party inspection report verifying OD, wall thickness, length and surface condition before container sealing
- Full material traceability from coil heat number through final bundle, with test reports available in English and Chinese
- Export customs package including packing list, bill of lading, certificate of origin and commercial invoice aligned with the destination country’s HS code for welded carbon steel pipe
Packaging, Loading & Delivery
- Q235 S355 ERW welded carbon steel round pipe bundled with galvanized steel strips and edge protectors to preserve the slightly oiled surface during ocean transit
- OD 32–219 mm pipes nested and strapped in seaworthy bundles sized to fit 20-foot and 40-foot open-top containers without exceeding port weight limits
- OD 325–1219 mm heavy-wall pipes loaded on flatbed trailers or break-bulk vessels with timber cradles to prevent ovalization during handling
- Custom cutting to 1–12 meter lengths per project drawing, with each bundle tagged by heat number, grade (Q235, Q355, A36) and wall thickness
- Shipping terms FOB Qingdao, CIF destination port or DDP project site, with full export documentation and container tracking until arrival
Getting a Firm Quote on Your Q235 S355 ERW Welded Carbon Steel Round Pipe
Send the outer diameter, wall thickness, length, grade and quantity to our team, and we return a detailed quotation with material cost, any processing fees and the shipping term you need — typically within twelve hours. If your drawing calls for a grade outside the standard list, or you need custom punching and bending, we confirm feasibility and lead time before you commit. The quote is accompanied by a sample mill test certificate format so your quality team can verify the documentation before the deposit is paid.
Frequently Asked Questions
Q: Can Q235 be substituted for A36 or S235JR on a structural drawing?
A: Q235, A36 and S235JR have similar yield ranges and are frequently treated as equivalent in general structural work, but the chemical composition and elongation must be verified against the specific standard your inspector enforces. We supply all three grades and provide the corresponding mill test certificate so the substitution is documented, not assumed.
Q: How do I verify the Q235 S355 ERW welded carbon steel round pipe matches the certificate?
A: Every pipe carries the heat number stamped on the surface, and the mill test certificate lists the same heat number with its chemical composition and mechanical test results. We also welcome SGS or BV third-party inspection at our facility before shipment, so an independent report confirms the match.
Q: What is the minimum order for custom-cut lengths?
A: The MOQ is 5 tons, and within that quantity we can cut to any length between 1 and 12 meters, punch holes, or bend to your drawing. Processing fees are quoted separately and appear on the proforma invoice before you pay the deposit.
Q: Does the slightly oiled surface protect the pipe for long-term outdoor storage?
A: The light oil applied after hot rolling protects the Q235 S355 ERW welded carbon steel round pipe during transit and short-term yard storage. For outdoor exposure beyond a few weeks, we recommend galvanizing or a 3PE coating, which we can arrange as a secondary processing step.
Q: How is wall-thickness tolerance controlled on ERW pipe?
A: The tolerance is ±1% across the full OD range of 32–1219 mm, verified by ultrasonic measurement at multiple points around the circumference. The mill test certificate and our dimensional inspection report both record the actual measured thickness, so there is no gap between the quoted and delivered wall.
Get Your Q235 S355 ERW Welded Carbon Steel Round Pipe Quote Today
Send your specification — grade, OD, wall thickness, length, quantity and destination port — and receive a detailed quotation with mill test certificate format within twelve hours.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.xjyplate.com
Tel: +86 531 8573 6315
Mobile / WhatsApp / WeChat: +86 188 5315 7756
Email: admin@xjyplate.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
