Description
Factory-Direct ERW Pipe Pricing — Q235 and Q345 grades produced on our own longitudinal seam lines, shipped without trading markups to EPC and piling contractors across 50+ countries.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235 Q345 ERW Longitudinal Seam Submerged Arc Welded Steel Pipe |
| Product Type | ERW Longitudinal Seam Submerged Arc Welded Steel Pipe (Round) |
| Steel Grade | Q235, Q345 |
| Standard | GB (API 5L referenced for piling pipe application) |
| Section Shape | Round |
| Size Range | OD 10–2620 mm |
| Wall Thickness | 0.5–80 mm |
| Length | 6 m / 12 m (or customized) |
| Technique | ERW / Longitudinal Seam Submerged Arc Welded (Hot Rolled) |
| Surface Treatment | Oiled / Coating / Thread / Groove / Beveled |
| Tolerance | ±1% |
| Ends | Plain / Beveled / Threaded / Grooved |
| Application | Structure Pipe / Port Construction / Piling / Construction / Bridge / Industrial Equipment |
| MOQ | 25 tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| EPC Contractors | Steel structure frames for industrial plants, pipe rack supports, equipment foundations |
| Construction Companies | Port piling, bridge pier casings, high-rise building columns, infrastructure retaining walls |
| Machinery Manufacturers | Heavy equipment roller frames, conveyor support columns, crane boom sections |
What Negative Tolerance Really Costs on a Piling Order
A pipe that passes the mill cert but fails the caliper at the port is a pipe you will pay twice for.
I have watched a full container of thick-wall welded pipe sit at Jebel Ali accumulating demurrage because the wall thickness ran past eight percent negative tolerance — the mill certificate looked clean, but the ultrasonic reading on-site told a different story. With Q235 Q345 ERW longitudinal seam submerged arc welded steel pipe used in load-bearing piling and port structures, even small deviations compound across dozens of heat numbers and turn a routine delivery into a customs and compliance headache. [NEED_CITE: EN 10219 dimensional tolerance requirements for welded hollow sections] Missing or inconsistent material traceability then blocks the engineer’s sign-off, and the cargo never leaves the quay.
Matching Wall Thickness and End Treatment to Piling and Structural Connections
Round ERW pipes in Q235 and Q345, spanning OD 10–2620 mm and wall thickness up to 80 mm, are sized to cover everything from light structural bracing to heavy piling casings. The ±1% tolerance and hot-rolled longitudinal seam submerged arc welding process give the weld zone enough integrity for driven piles and compression columns, while the choice of plain, beveled, threaded, or grooved ends lets site crews match the connection method — welding, mechanical coupling, or flange bolting — without secondary machining. Q235 Q345 ERW longitudinal seam submerged arc welded steel pipe supplied this way arrives on-site ready to go straight into the template.
Engineering Compliance Across Port, Bridge, and Industrial Frames
Piling and port construction typically call for compliance with GB standards, with API 5L referenced where the pipe doubles as a casing in marine-driven piles. For projects entering the EU or North America, the same Q235 Q345 ERW longitudinal seam submerged arc welded steel pipe can be cross-referenced against EN 10219 or ASTM A500 equivalence tables, though the mill test certificate must clearly show the chemical and mechanical basis of the grade mapping. [NEED_CITE: steel grade equivalence between GB Q-series and EN ASTM standards] Surface treatment — oiled for inland transit, coating for marine exposure, beveled or grooved for welded or mechanical joints — is selected against the corrosion environment the pipe will face once it is in the ground or submerged.
Why Q235 and Q345 Behave Differently Under Load
Q235 and Q345 belong to the Chinese GB grade system, where the number roughly indicates the minimum yield strength class. On a structural frame, Q345 carries higher design loads with the same cross-section, which is why piling and bridge piers often specify it over Q235. The hot-rolled ERW longitudinal seam submerged arc welding process fuses the seam under sustained heat and pressure, producing a weld line whose mechanical properties stay close to the parent metal — a meaningful advantage over cold-formed alternatives when the pipe is driven or subjected to dynamic loads. Wall thickness up to 80 mm, held within ±1% tolerance, keeps the theoretical weight aligned with the actual weight, so invoicing by actual weight reflects what the crane actually lifts. [NEED_CITE: submerged arc welding integrity in thick-wall ERW pipe]
The Hidden Price of Buying the Wrong Grade or Skipping Inspection
Specifying Q235 where Q345 is required does not show up until the structural engineer reviews the mill test certificate — by then the pipe is already on-site, and replacement means cutting out driven piles or rewelding connections. Missing third-party inspection or an incomplete MTC can stall customs clearance in the EU or the Middle East, because officers check the CE mark and the heat-number traceability before releasing heavy cargo. [NEED_CITE: customs documentation requirements for structural steel pipe imports] The real cost is never the unit price difference between grades; it is the idle rig, the rescheduled pour, and the reissued drawing set.
Why Contractors and Distributors Source Q235 Q345 ERW Longitudinal Seam Submerged Arc Welded Steel Pipe Through Us
Our three dedicated production lines cover more than 2,800 specifications, so a single order mixing Q235 structural sections and Q345 piling casings ships from one yard rather than three suppliers. Every heat runs through our in-house physical and chemical laboratory before it leaves Jinan, and the resulting mill test certificate travels with the container — the same check I wish had been done on that Jebel Ali cargo years ago. We hold ISO 9001:2015, Lloyd’s Register EU CE certification under EN 10210 and EN 10219, and Singapore FPC, with SGS and BV third-party inspection available on request. Custom non-standard OD, wall thickness, and length are cut to drawing, and our loading team plans each container around the 6 m and 12 m lengths to avoid port-side rehandling.
Documentation & Compliance
- Mill test certificate documenting Q235 and Q345 chemical composition and mechanical properties per GB, with heat-number traceability
- CE certificate covering EN 10210 and EN 10219 for projects entering the European Economic Area
- ISO 9001:2015 quality management certificate covering the full ERW longitudinal seam submerged arc welded pipe production line
- SGS or BV third-party inspection report issued before shipment, confirming OD, wall thickness, and weld-seam integrity
- Material traceability sheet linking each pipe to its heat number, production date, and laboratory test batch
- Full customs document set including packing list, bill of lading, and certificate of origin for the destination country
Packaging, Loading & Delivery
- Q235 and Q345 round pipes bundled with steel strips and edge protectors, sized to match the 6 m and 12 m fixed lengths for stable ocean transit
- Oiled or coated surface treatment preserved by waterproof wrapping and wooden cradles to prevent coating damage during handling
- Container loading plan optimized around OD 10–2620 mm and wall thickness up to 80 mm, nesting smaller diameters inside larger ones where the design allows
- Custom cut-to-length service available for non-standard piling or structural requirements, with ends beveled, threaded, or grooved to drawing
- Heat number and Q235/Q345 grade stenciled on each pipe end for fast site identification and traceability during installation
- FOB, CIF, and DDP terms with door-to-door coordination to ports across the EU, North America, the Middle East, and Southeast Asia
Getting a Firm Offer on Q235 Q345 ERW Longitudinal Seam Submerged Arc Welded Steel Pipe
Send the specification sheet — OD, wall thickness, length, steel grade, end treatment, quantity, and destination port — and the reply within twelve hours includes unit price, production lead time, applicable certifications, and a draft mill test certificate format. For non-standard sizes or mixed-grade piling orders, the engineering team returns a cut-to-drawing proposal with the loading plan before the deposit is paid.
Frequently Asked Questions
Q: What is the difference between Q235 and Q345 for structural and piling use?
A: Q235 and Q345 are GB standard carbon and low-alloy structural steels, with Q345 offering a higher yield strength class suitable for heavier load-bearing applications such as piling, bridge piers, and port structures. The choice depends on the design load and the engineer’s specification, and both grades are supplied with full chemical and mechanical test data.
Q: Can you provide third-party inspection before shipment?
A: Yes. SGS and BV third-party inspections are available on every order of Q235 Q345 ERW longitudinal seam submerged arc welded steel pipe, covering dimensional checks, weld-seam quality, and surface treatment verification before the container is sealed.
Q: Do you supply non-standard OD and wall thickness outside the 10–2620 mm / 0.5–80 mm range?
A: Custom non-standard dimensions are produced to drawing, subject to MOQ and production line feasibility. The engineering team reviews the request and confirms whether the specification falls within the 2,800+ models we cover or requires a dedicated setup.
Q: Which surface treatment is recommended for marine piling?
A: For marine and port piling, coating or heavy-duty oiled protection is typically specified to resist saltwater corrosion during driving and in-service life. The exact choice depends on the soil chemistry and design life, and the mill test certificate confirms the coating thickness and adhesion results.
Q: What documents are provided for customs clearance?
A: Each shipment includes the mill test certificate, packing list, bill of lading, certificate of origin, and, where required, the CE certificate under EN 10210/EN 10219 and third-party inspection report, so the cargo clears without delays at the destination port.
Request Your Q235 Q345 ERW Pipe Quote with Mill Test Certificate
Submit your OD, wall thickness, length, grade, and destination port to receive a detailed quotation and draft MTC within twelve hours. Contact Shandong Xin Jiyuan Special Steel Tube Co., Ltd at +86 188 5315 7756 or admin@sdxjysteel.com.
