Description
Factory-direct ERW welded round carbon steel pipe supplier — 3 production lines and 2,800+ raw material specifications under one roof, from billet to finished pipe.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235 Q345 A36 S235JR ERW Welded Round Steel Pipe |
| Product Type | ERW Welded Round Steel Pipe |
| Steel Grade | Q235, Q345, SS400, A36, A572, S235JR, S355J2 |
| Standard | ASTM, JIS, API, ISO 9001, CE, GS |
| Section Shape | Round |
| Size Range | Outer Diameter 10–2000 mm |
| Length | 6 m / 6.4 m / 12 m |
| Technique | ERW (Electric Resistance Welded) |
| Surface Treatment | Hot Rolled / Cold Rolled, Black / Bright / Galvanized / Painted |
| Tolerance | ±1% |
| Oiled or Non-oiled | Non-oiled |
| Invoicing | By Theoretical Weight |
| Processing Service | Welding, Punching, Cutting, Bending, Decoiling |
| Application | Fluid transport, Oil & Gas pipeline, Hydraulic systems, Boiler, Drill pipe, Chemical fertilizer plant, Construction structure, Bridge piling, Water supply and drainage |
| MOQ | 10 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Infrastructure & Civil Engineering | Bridge piling, foundation casing, retaining wall structures |
| Oil & Gas / Petrochemical | Pipeline transport, chemical fertilizer plant piping, drill pipe casing |
| Water Conservancy | Water supply mains, drainage networks, irrigation infrastructure |
| Construction & Structural | Building frames, column supports, construction structure assemblies |
| Industrial & Hydraulic | Hydraulic systems, boiler tubes, industrial fluid transport lines |
What Negative Tolerance Really Costs on a Bridge Piling Order
Wall-thickness deviation beyond ±1% turns a theoretical-weight invoice into a structural liability.
On bridge piling projects across Southeast Asia, I have seen ERW welded round carbon steel pipe arrive at site with wall thickness drifting past the acceptable negative tolerance. The pipes looked right on paper — invoiced by theoretical weight, certificates in hand — but ultrasonic re-check at the pile cap level told a different story. Sections that should carry designed compressive loads fell short, and the contractor faced a choice: accept reduced bearing capacity or tear out driven piles and reorder. [NEED_CITE: EN 10219 dimensional tolerance requirements for structural hollow sections]
The root cause is almost always fragmented sourcing. When the trading company buying from one mill and the fabricator buying from another never share the same quality system, negative tolerance creeps in silently. Our vertically integrated model — own steel mill feeding directly into our fabrication division — closes that gap. Every heat number traces back to our production line, and every batch passes through our in-house thickness gauging before it leaves Jinan.
How OD Range and Steel Grade Match Piling and Pipeline Demands
Bridge piling typically calls for large-diameter pipe — 500 mm to 2000 mm OD — in grades like Q345 or A572 where higher yield strength handles driving stresses and soil bearing loads. Oil and gas pipelines, by contrast, run smaller diameters with tighter seam integrity requirements, favoring S235JR or S355J2 under EN frameworks or A36 and A572 under ASTM. As an ERW welded round carbon steel pipe supplier controlling the full chain from raw material to finished product, we match grade selection to the structural or pressure requirement of each application, rather than offering a one-size catalogue.
Structural Code Compliance and Surface Protection in Corrosive Environments
Engineering specifications for piling and structural frames reference design codes such as EN 1993 or AISC, which demand certified material properties and documented weld seam quality. [NEED_CITE: AISC code requirements for structural steel material certification] For water drainage and irrigation infrastructure exposed to soil moisture or chemical fertilizer plant environments, surface treatment selection becomes critical — black pipe for indoor or temporary use, galvanized coating for atmospheric corrosion resistance, or painted systems for buried or submerged conditions. ERW welded round carbon steel pipe in S355J2 or Q345 with appropriate coating can meet both the structural load path and the corrosion protection specification in a single procurement package. CE certification and EN-compliant mill test documentation determine whether the shipment clears EU customs or gets held for re-inspection.
ERW Process, Grade Systems, and What Tolerance Means for Load-Bearing
The ERW welding process forms round pipe from coil or plate through progressive rolling and fuses the seam via electric resistance heating — no filler metal, no flux. When ultrasonic and X-ray inspection confirm seam integrity, ERW pipe delivers reliable performance for structural and medium-pressure applications at lower cost than seamless alternatives. Steel grade selection follows three major systems: Chinese Q-series (Q235, Q345), European S-series (S235JR, S355J2), and American ASTM grades (A36, A572). Each system defines yield strength tiers — S-series and Q-series both step upward in roughly 50–100 MPa increments — and selecting the right grade directly affects section capacity and connection design. [NEED_CITE: steel grade equivalence mapping between GB, EN, and ASTM standards] The ±1% OD tolerance on our ERW welded round carbon steel pipe ensures that fit-up at welded connections and pile shoe details remains within fabrication tolerances, avoiding costly field rework.
The Hidden Cost of Unverified Mill Test Certificates
Pipes with missing or forged mill test certificates pass visual inspection at the port but fail at the engineering audit stage — sometimes after they have already been welded into the structure. Material traceability gaps mean the contractor cannot prove grade compliance to the project engineer, triggering rejection or mandatory third-party re-testing at the buyer’s expense. [NEED_CITE: EN 10204 inspection document types for steel products] When negative tolerance exceeds the nominal ±1% range, the actual weight — and therefore the actual section modulus — drops below design assumptions, creating a structural safety risk that no amount of paperwork can resolve after installation.
Why Procurement Teams Source ERW Welded Round Carbon Steel Pipe from XJY Structure
Our own steel mill with 3 production lines and over 2,800 raw material specifications means the pipe you order is produced, welded, tested, and documented within a single quality system — no material sourcing gaps between an outside mill and a separate fabricator. In-house thickness gauging, ultrasonic seam inspection, and dimensional checks run on every production batch before packing. We hold CE certification, ISO 9001 quality management registration, and welcome SGS, BV, or TUV third-party inspection on any order. For projects requiring shop drawing coordination or custom cutting and bending, our fabrication division handles processing services — welding, punching, cutting, bending, decoiling — so the pipe arrives on site ready to install. Professional oversized cargo loading and export documentation complete the delivery chain from Jinan to your project port.
Documentation & Compliance
- Mill Test Certificate (EN 10204 3.1/3.2) documenting Q235, Q345, A36, or S235JR chemical composition and mechanical properties per applicable standard
- CE certificate confirming compliance with EN 10219 for structural hollow sections used in EU construction projects
- ISO 9001 quality management system certificate covering the full production process from raw material to finished ERW welded round steel pipe
- SGS / BV / TUV third-party inspection report available upon request for dimensional verification, coating thickness, and weld seam NDT
- Full material traceability by heat number from our own steel mill through to the finished pipe bundle
- Customs documentation package including packing list, bill of lading, and certificate of origin for destination-country clearance
Packaging, Loading & Delivery
- ERW welded round carbon steel pipe bundled with steel strips and edge protectors, sized to match 6 m, 6.4 m, or 12 m lengths for efficient container or break-bulk loading
- Galvanized pipes packed with protective separators to preserve the zinc coating during ocean transit; black and painted pipes shipped non-oiled per specification
- Large-diameter pipe (500–2000 mm OD) loaded on cradles or in flat-rack containers with professional lashing for oversized cargo transport
- Heat number and steel grade stenciled on each pipe end for on-site identification and traceability verification
- FOB, CFR, CIF, and DDP delivery terms available with full export documentation and shipment tracking to project site
- Custom cutting to project-specific lengths available before packing to reduce on-site waste and welding joints
Start Your Procurement with Drawings and Specifications
Submit your project drawings (PDF or DWG), required steel grades, outer diameter and length specifications, quantity, and destination port. Our team responds within 24 hours with a detailed quotation covering material, fabrication, coating, packing, and shipping costs — along with a shop drawing timeline and production schedule. Confirm your certification requirements and third-party inspection needs at the inquiry stage so documentation is prepared in parallel with production.
Frequently Asked Questions
Q: What is the difference between Q235, A36, and S235JR — which grade should I specify?
A: Q235, A36, and S235JR are equivalent structural grades from the Chinese GB, American ASTM, and European EN systems respectively, with similar yield strength levels. The correct choice depends on which design code your project engineer is working to. We supply all three and can advise on equivalence mapping for your specification.
Q: Can you arrange third-party inspection before shipment?
A: Yes. SGS, BV, and TUV third-party inspections are available on request. We coordinate the inspection schedule with production so that dimensional checks, coating thickness measurement, and weld seam NDT are completed before the pipes leave our facility.
Q: How do you ensure wall thickness stays within tolerance?
A: Every batch passes through in-house ultrasonic thickness gauging on our production line. Our vertically integrated model — own steel mill feeding directly into pipe fabrication — means we control the process from raw material to finished pipe, with no third-party sourcing gaps that allow negative tolerance to drift.
Q: What surface treatment options are available for corrosive environments?
A: We offer black (as-produced), bright, hot-dip galvanized, and painted surface treatments. Galvanized coating suits atmospheric and moderate corrosion environments; painted systems can be specified for buried or submerged conditions such as water drainage and irrigation infrastructure.
Q: What is the minimum order quantity?
A: The MOQ is 10 Tons. For project orders requiring multiple grades, diameters, or lengths, we consolidate production across our 2,800+ raw material specifications to meet your full bill of materials in a single shipment.
Get Your ERW Welded Round Carbon Steel Pipe Quote Today
Send your project specifications, steel grade requirements, and destination port to receive a detailed quotation with mill test certificate documentation within 24 hours.
Company: Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.xjystructure.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@xjystructure.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
