Description
Factory-Direct ERW Pipe Source — 3 production lines running simultaneously with monthly capacity exceeding 20,000 tons, eliminating middlemen markups on Q235 Q355 ERW welded steel pipe orders.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235 S355 ERW Welded Steel Pipe |
| Product Type | ERW Welded Steel Pipe / Round Steel Pipe |
| Steel Grade | Q195, Q235, Q355, S355, 10#, 20#, 45#, 16Mn, A53, A36, ST35, ST52 |
| Standard | API 5L, ASTM A53, ASTM A252, ASTM A671, ASTM A450, ASME B36.10M, BS 1387, BS EN 10296, BS EN 10219, GB/T 3091, GB/T 13793, GB/T 9711 |
| Section Shape | Round |
| Outer Diameter | 6–1820 mm |
| Wall Thickness | Cold rolled 1–4.0 mm / Hot rolled 4–20 mm |
| Length | 1–12 m (standard 6 m, 12 m) |
| Technique | ERW / Hot Rolled / Cold Rolled |
| Surface Treatment | Hot Rolled / Slightly Oiled |
| Tolerance | ±1% |
| Ends | Plain (default) |
| Application | Fluid transport / Gas & oil pipeline / Boiler / Hydraulic systems / Chemical fertilizer / Construction / Machinery / Building industry |
| MOQ | 5 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Oil & Gas Pipeline | Fluid conveyance lines, gas distribution networks, API 5L grade pipeline systems |
| Construction & Infrastructure | Structural frames for commercial buildings, scaffolding tubes, piling supports |
| Industrial Equipment | Boiler tubes, hydraulic cylinder sleeves, chemical fertilizer processing lines |
| Machinery Manufacturing | Conveyor rollers, equipment base frames, hydraulic system components |
Tolerance Drift on ERW Pipe: The Hidden Cost of “Close Enough”
A ±1% tolerance on a 12-meter Q355 round pipe translates to measurable weight deviation across a full-container order — and that deviation compounds when site engineers verify with calipers.
I have seen entire shipments held at West African ports because wall thickness fell outside the acceptable band. The supplier quoted a competitive price by pushing negative tolerance to the limit, but the project监理 pulled random samples, measured with ultrasonic gauges, and rejected the lot. The buyer paid for return freight, replacement production, and three weeks of idle crane time. When sourcing a Q235 Q355 ERW welded steel pipe for structural or pressure applications, tolerance is not a footnote — it is the difference between passing inspection and eating margin. [NEED_CITE: EN 10219 dimensional tolerance requirements for cold-formed welded hollow sections]
Matching ERW Round Pipe to Structural and Pipeline Demands
A Q235 Q355 ERW welded steel pipe in the 6–1820 mm OD range covers the majority of fluid transport and structural framing requirements across developing-economy infrastructure projects. The ERW process produces a consistent longitudinal weld seam suitable for moderate-pressure fluid conveyance, while the hot-rolled wall thickness options from 4 mm to 20 mm handle load-bearing structural columns and piling applications. Slightly oiled surface treatment provides short-term corrosion protection during ocean transit and on-site storage before final coating or welding.
Engineering Compliance and Certification Requirements
Structural applications in the EU require CE marking under EN 10219 for cold-formed welded sections, and project specifiers increasingly request Factory Production Control certificates alongside mill test documentation. For pipeline work conforming to API 5L or ASTM A53, heat-number traceability on every mill test certificate is non-negotiable at customs and during client handover. The Q355 and S355 grades specified here meet the yield strength tiers commonly called for in EN 1993-1-1 structural design codes, while A53 and API 5L grades satisfy North American and international pipeline standards respectively. [NEED_CITE: steel grade equivalence mapping between GB/T Q-series and EN S-series standards]
Steel Grade Selection and ERW Process Fundamentals
The Q-series (Q195, Q235, Q355) follows the Chinese GB/T designation system where the number indicates minimum yield strength in MPa. Q235 serves general structural and low-pressure fluid applications, while Q355 provides higher load capacity for heavy structural frames and bridge components. The S-series (S355) and ASTM equivalents (A36, A53) cover the same performance tiers under European and American standards respectively — specifying the correct designation for your destination market avoids customs documentation mismatches. [NEED_CITE: comparative yield strength ranges across Q235, S235JR, and A36 designations]
ERW welding forms the pipe by rolling steel strip into a cylinder and passing high-frequency current through the open edges to forge-weld the seam. This process suits large-diameter production (up to 1820 mm OD) with tight dimensional control and lower cost than seamless alternatives. For wall thickness below 4 mm, cold rolling delivers a smoother surface finish ideal for precision machining; hot rolling above 4 mm provides the thickness uniformity needed for structural load paths. The slight oiling applied after production prevents flash rust during the typical 15–25 day production and shipping window.
What Happens When You Buy the Wrong Grade or Unverified Pipe
Ordering Q235 when the structural engineer specified Q355 means the pipe yields under design load — a failure that does not announce itself until deflection becomes visible or connections loosen. Conversely, over-specifying Q355 for a non-structural fluid line wastes budget on unnecessary strength. Missing or incomplete mill test certificates trigger customs holds in markets with strict import documentation requirements, while untraceable heat numbers void project warranty claims. [NEED_CITE: consequences of non-conforming steel materials in structural engineering projects]
Procurement Confidence from a Verified Mill Source
Every batch of Q235 Q355 ERW welded steel pipe ships with original mill test certificates traceable to the heat number, verified by our in-house metallurgical laboratory before release. We operate three production lines simultaneously, covering over 2,800 specifications in ready stock — this means standard OD and wall thickness combinations ship within days, while custom cut-to-length or non-standard dimensions complete within typical production lead times. Lloyd’s CE certification under EN 10210 and EN 10219, ISO 9001:2015 registration, and FPC documentation satisfy EU customs and project compliance requirements without third-party broker fees. SGS and BV inspection teams are welcome at our facility for pre-shipment verification on any order volume. Our professional export team handles container loading optimization — critical when shipping 12-meter lengths in 40-foot containers where improper nesting wastes cubic capacity and drives freight cost per ton upward.
Documentation & Compliance
- Mill test certificate documenting Q235/Q355 chemical composition and mechanical properties per GB/T 3091, traceable to individual heat number
- CE certificate covering EN 10219 cold-formed welded structural hollow sections for EU market customs clearance
- ISO 9001:2015 quality management certificate covering full production and inspection process
- SGS or BV third-party inspection report available upon request for pre-shipment quality verification
- Full customs documentation package including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- ERW welded round pipes bundled with steel strips in seaworthy packaging, with edge protectors for oiled surface preservation during ocean transit
- Standard 6 m and 12 m lengths optimized for 40-foot container loading with professional nesting plans to maximize cubic utilization
- Heat number and steel grade stenciled on each pipe end for on-site identification and traceability verification
- Slightly oiled surface treatment applied post-production to prevent flash rust during typical production and shipping timelines
- FOB, CIF, and DDP shipping terms available with real-time tracking and professional export documentation handling
Getting Your Quotation Started
Submit your required outer diameter, wall thickness, steel grade, total tonnage, and destination port — we return a competitive bulk quotation with volume pricing, delivery timeline, and available mill test certificate documentation within 12 hours. For non-standard dimensions or custom cut-to-length requirements, share your drawing or specification sheet and we confirm feasibility and lead time.
Request Your Q235 Q355 ERW Welded Steel Pipe Quotation
Send your specifications via email or WhatsApp to receive factory-direct pricing, available mill test certificates, and container loading optimization for your next bulk order.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.sdxinjiyuan.com
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@sdxinjiyuan.com
