Description
Factory-Direct Pricing, No Middlemen — Every Q235 carbon steel welded round pipe leaves our own mill in Jinan, priced at production cost with full traceability from billet to finished length.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235 Carbon Steel Welded Round Steel Pipe |
| Product Type | Welded Round Steel Pipe |
| Steel Grade | Q195, Q235, Q355, 10#, 20#, 45#, 16Mn, 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 EN10296, BS 6323, BS 6363, BS EN10219, GB/T 3091, GB/T 13793, GB/T 9711 |
| Section Shape | Round |
| Outer Diameter | 10–700 mm |
| Wall Thickness | Cold rolled 1–4.0 mm / Hot rolled 4–20 mm |
| Length | 1–12 m |
| Technique | Hot rolled, Cold rolled, Cold drawn |
| Surface Treatment | Hot Rolled |
| Tolerance | ±1% |
| Ends | Plain End, Beveled, Threaded |
| Application | Fluid transport, Boiler, Drill pipe, Hydraulic system, Gas pipeline, Oil pipeline, Chemical fertilizer, Structure pipe, Building industry, Machinery |
| MOQ | 10 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| EPC Contractors | Fluid, gas, and oil pipeline systems for energy infrastructure and industrial plant projects |
| Construction Companies | Structural round pipes for building frames, scaffolding systems, and bridge support columns |
| Machinery Manufacturers | Hydraulic cylinders, conveyor rollers, and equipment chassis requiring precision bore |
| System Integrators | Automation frames, material handling racks, and industrial piping networks |
What Wall-Thickness Tolerance Costs on a Structural Frame Order
A ±1% tolerance on a Q235 welded round pipe is the difference between passing site inspection and scrapping an entire container.
When procurement teams source welded round pipes from fragmented suppliers, inconsistent wall thickness is the first defect to surface on-site. Ultrasonic gauges catch pipes below minimum spec, triggering rejection orders that delay crane schedules and idle welding crews. Missing mill test certificates compound the problem — without heat-number traceability, customs officers hold cargo at the port, and engineers refuse to sign off on load-bearing joints. I have seen entire batches returned because the supplier gambled on negative tolerance limits and lost. A Q235 carbon steel welded round pipe produced under controlled rolling conditions, verified by an in-house physical and chemical laboratory, eliminates that gamble. [NEED_CITE: EN 10219 dimensional tolerance requirements for cold-formed welded hollow sections]
Matching OD and Wall Thickness to Pipeline and Structural Loads
A Q235 carbon steel welded round pipe in the 10–700 mm OD range covers everything from small-bore hydraulic lines to large-diameter fluid mains. For EPC contractors building gas or oil pipeline systems, the hot-rolled wall thickness range of 4–20 mm handles working pressures typical of mid-stream transmission, while cold-rolled 1–4.0 mm sections serve low-pressure instrument and control lines. The ±1% tolerance ensures that when a structural engineer specifies a 219 mm × 8 mm column for a building frame, every delivered length carries the designed load without surprise deflection. Our 3 dedicated production lines and in-house lab testing confirm dimensional accuracy before any pipe leaves the mill.
Engineering Compliance Across EN, ASTM, and GB Frameworks
Structural projects in the EU require CE certification under EN 10210 or EN 10219, while North American EPCs specify ASTM A53 or API 5L. A Q235 carbon steel welded round pipe that conforms to multiple standard systems — including GB/T 3091, BS EN10219, and ASTM A53 — allows procurement teams to consolidate orders across regions without re-qualifying material. End treatments (plain, beveled, threaded) match field welding, mechanical coupling, or threaded connection methods specified in AISC or EN 1993 design codes. Third-party inspection via SGS or BV before shipment provides independent verification for project owners and lenders. [NEED_CITE: steel grade equivalence between EN and ASTM standards for structural hollow sections]
Decoding Q235, Q355, and ASTM A53 Grade Selection
Q235 sits at the entry point of the Chinese structural steel family — its yield strength suits general construction, scaffolding, and low-pressure fluid conveyance. Q355 steps up for heavier structural frames and bridge components where higher load capacity is required. When projects specify ASTM A53 Grade B or API 5L Grade B, the chemical composition and mechanical properties of Q235 and Q355 map closely enough to allow direct substitution in many applications, subject to engineer approval. Hot-rolled surfaces retain mill scale that provides short-term rust resistance during storage and transit, while cold-rolled and cold-drawn finishes deliver tighter dimensional control for precision machining and hydraulic bore applications. The choice between hot-rolled and cold-rolled Q235 carbon steel welded round pipe depends on whether the priority is cost-effective structural use or tight-tolerance mechanical integration.
The Hidden Cost of Unverified Material and Missing Certificates
Pipes sourced without original mill test certificates or third-party inspection reports create downstream risk that dwarfs any upfront price saving. Customs authorities in the EU and Middle East routinely hold steel shipments lacking CE documentation or proper heat-number traceability, generating demurrage charges and project delays. On-site, when ultrasonic testing reveals wall thickness below the specified tolerance, the entire batch fails acceptance — and replacing 20 tons of pipe mid-project costs far more than the original purchase price. A Q235 carbon steel welded round pipe backed by ISO 9001 quality management, in-house lab testing, and SGS/BV verification protects the project schedule and the engineer’s signature. [NEED_CITE: consequences of non-compliant steel imports on construction project timelines]
Why Engineering Teams Source Welded Round Pipe From Our Mill
Our Jinan facility operates 3 dedicated production lines covering over 2,800 specifications, with wall thickness up to 40 mm — including the 10–700 mm OD and 1–20 mm WT range of this Q235 carbon steel welded round pipe. Factory-direct pricing means no trading margin between the rolling mill and your project site. Our in-house physical and chemical laboratory tests every heat for composition, yield strength, and dimensional accuracy, generating original mill test certificates with full traceability. We hold CE certification under EN 10210/10219 for EU market compliance, ISO 9001:2015 for quality systems, and accept SGS or BV third-party inspection before shipment. Custom non-standard sizes, end treatments, and cutting services are available for projects that fall outside catalog ranges. Professional container loading optimization and door-to-door logistics cover FOB, CIF, and DDP terms to 50+ countries.
Documentation & Compliance
- Mill test certificate documenting Q235 chemical composition, yield strength, and tensile properties per GB/T 700 and ASTM A53 requirements
- CE certificate under EN 10210/10219 for structural hollow sections exported to EU member states
- ISO 9001:2015 quality management certificate covering the full production and inspection process
- SGS or BV third-party inspection report available upon request for pre-shipment verification
- Material traceability by heat number linking each pipe to its original mill test certificate
- Customs documentation package including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- Hot rolled Q235 welded round pipes bundled with steel strips and edge protectors to prevent surface damage during ocean transit
- Plain-end, beveled, and threaded ends capped with plastic protectors to preserve thread integrity and prevent moisture ingress
- Container loading optimized for 1–12 m lengths to maximize payload per 20ft or 40ft container, reducing freight cost per ton
- Custom cutting to project-specified lengths available, with cut ends deburred and marked with heat number and steel grade
-唛头 stenciled on each bundle showing steel grade (Q235/Q355/A53), OD × WT, length, heat number, and destination port
- FOB, CIF, and DDP terms supported with professional logistics coordination to ports across the EU, North America, Middle East, and Southeast Asia
Request a Quote With Mill Test Certificate and Loading Plan
Submit your required OD, wall thickness, steel grade, quantity, and destination port — we respond within 12 hours with unit pricing, production lead time, applicable certifications, and a preliminary container loading plan. For non-standard dimensions outside the 10–700 mm OD range, our engineering team provides custom fabrication options with MOQ confirmation.
Start Your Q235 Welded Round Pipe Inquiry
Send your specifications via email or WhatsApp to receive a detailed quotation, original mill test certificate sample, and third-party inspection arrangement.
Contact: admin@sdxjysteel.com | WhatsApp: +86 188 5315 7756
