Description
Direct Mill Supply, No Middlemen — XJY Structure operates its own steel production facility with 3 ERW lines, delivering Q235B/Q345B ERW carbon steel round pipes with full material traceability from billet to finished tube.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235B/Q345B ERW Round Steel Pipe |
| Product Type | ERW Round Steel Pipe / Circular Hollow Section |
| Steel Grade | Q235, Q235B, Q345, Q345B, SS400, ASTM A53 (A/B), ASTM A106 (B/C), API 5L (Gr.A, Gr.B, X42, X52, X60, X70), S235JR, S275JR, S355J2, A53-A369, Q195 |
| Standard | ASTM A213-2001, DIN EN 10217-1-2005, JIS, GB, EN, API 5L |
| Section Shape | Round |
| Size Range | Outer Diameter 14–1200 mm |
| Wall Thickness | 1–50 mm |
| Length | 6 m / 12 m (customized available) |
| Technique | ERW / Hot Rolled / Cold Rolled |
| Surface Treatment | Black Painted / Varnished / Galvanized (Hot-Dip / Electro) / 3LPE / 3LPP Coated / Oiled |
| Tolerance | ±1% |
| Ends | Plain / Beveled / Threaded |
| Application | Fluid transport / Gas pipeline / Oil pipeline / Construction structural frameworks / Scaffolding / Machinery / Shipbuilding / Automotive |
| MOQ | Negotiable |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Oil & Gas | Transmission pipelines, distribution networks, gathering lines |
| Construction | Building frames, column supports, scaffolding systems, conveyor structures |
| Machinery | Hydraulic cylinders, pneumatic systems, machine frames |
| Shipbuilding | Marine piping, offshore platform supports, ballast systems |
| Infrastructure | Bridge handrails, utility poles, structural bracing |
Wall Thickness Variance: The Hidden Cost of ±1% Tolerance on ERW Carbon Steel Round Pipe Orders
Tight dimensional control separates project-ready pipe from site-rejected material.
When sourcing ERW carbon steel round pipe from overseas fabricators, buyers face a recurring problem: wall thickness readings that drift below nominal, triggering third-party inspection failures at destination ports. A 2% negative deviation on a 12mm wall pipe means 0.24mm lost — enough to fail EN 10219 dimensional checks or API 5L hydrostatic test requirements [NEED_CITE: EN 10219 cold-formed hollow section dimensional tolerance requirements]. Beyond rework costs, material rejection delays project schedules and erodes contractor credibility with end clients.
Matching ERW Carbon Steel Round Pipe to Structural and Pressure Applications
Q235B and Q345B grades cover the majority of structural framing and low-pressure fluid transport requirements across Southeast Asian and Middle Eastern projects. For ERW carbon steel round pipe used in scaffolding and building frames, the ±1% tolerance ensures consistent load-bearing capacity across batch quantities. When projects specify API 5L X42 or X52 for gas transmission, the ERW weld seam must pass full ultrasonic testing per API 5L requirements — a checkpoint our integrated mill handles in-line rather than outsourcing to third-party NDT providers.
Engineering Compliance: EN, ASTM, and API Standards for ERW Carbon Steel Round Pipe
Structural applications in EU markets require EN 10219 compliance for cold-formed hollow sections, while North American projects typically specify ASTM A53 or A500. The ERW carbon steel round pipe we produce meets DIN EN 10217-1 for pressure purposes and ASTM A213 for high-temperature service [NEED_CITE: steel grade equivalence between EN 10217 and ASTM A213 standards]. Surface treatment selection — black painted for indoor structural use, hot-dip galvanized for outdoor exposure, or 3LPE coating for buried pipelines — directly impacts service life and maintenance intervals. Custom lengths beyond standard 6m or 12m reduce on-site welding joints, lowering labor costs and potential leak paths.
Steel Grade Selection and ERW Process Fundamentals
Q235B (equivalent to S235JR per EN 10025) provides adequate strength for general structural frames and scaffolding, while Q345B (S355JR equivalent) delivers higher yield strength for load-bearing columns and crane beams. The ERW process forms round pipe from skelp coil through continuous forming and high-frequency electric resistance welding — producing a longitudinal weld seam with properties matching the base metal when properly normalized. For API 5L grades X42 through X70, the ERW weld zone undergoes online heat treatment to restore toughness and eliminate soft zones [NEED_CITE: ERW weld seam heat treatment requirements for API 5L line pipe]. Wall thickness tolerance directly affects theoretical weight calculations: a 108mm × 6mm pipe invoiced by actual weight will vary ±1% per our specification, meaning buyers receive what they pay for rather than absorbing negative tolerance losses.
The True Cost of Non-Compliant ERW Carbon Steel Round Pipe
Material substitution — receiving Q195 instead of Q235B, or S235JR instead of S355J2 — creates structural safety risks that surface only during load testing or service failure. Missing mill test certificates or incomplete heat number traceability triggers customs holds in EU markets requiring CE marking under EN 10219 [NEED_CITE: CE marking requirements for structural steel hollow sections]. Negative tolerance beyond contractual limits forces costly re-engineering or complete batch replacement, with logistics costs often exceeding the original pipe value. Third-party inspection reports from SGS or BV confirm chemical composition and mechanical properties before shipment — a verification step that prevents destination-port disputes.
Why Procure ERW Carbon Steel Round Pipe from XJY Structure
Our vertically integrated operation eliminates the gap between raw material supplier and pipe fabricator — the same facility that produces the steel coil also forms, welds, and tests the finished ERW carbon steel round pipe. With 2,800+ raw material specifications in inventory, we maintain stock of Q235B, Q345B, and API 5L grades in common OD/Wall combinations, enabling typical production lead times for standard orders. Every heat number traces back to our mill’s chemical analysis and mechanical test records, documented in EN 10204 3.1 format mill test certificates. For projects requiring third-party verification, we coordinate SGS, BV, or TÜV inspections at any production stage — from coil edge preparation through final dimensional checks. Custom surface treatments (hot-dip galvanizing, 3LPE coating, or specialized painting) are applied in-house under controlled conditions, with coating thickness reports included in the documentation package. Professional loading plans optimize container utilization for 6m and 12m lengths, reducing freight costs per ton.
Documentation & Compliance
- Mill test certificate documenting Q235B/Q345B chemical composition and mechanical properties per GB/T 700 or EN 10025
- CE certificate confirming EN 10219 compliance for structural hollow sections exported to EU markets
- ISO 9001 quality management system certificate covering ERW pipe production and testing processes
- SGS or BV third-party inspection report verifying wall thickness, OD tolerance, and weld seam quality
- Material traceability by heat number linking each pipe bundle to coil chemistry and rolling records
- Customs documents including packing list, bill of lading, and certificate of origin for destination clearance
Packaging, Loading & Delivery
- ERW carbon steel round pipe bundled with steel strips and edge protectors to prevent surface damage during ocean transit
- Black painted or oiled surfaces wrapped in waterproof paper; galvanized pipes separated by rubber spacers to preserve zinc coating
- 6m and 12m lengths loaded in 20ft or 40ft containers with optimized stowage plans maximizing weight utilization
- Custom cut lengths available for OD 14–1200mm range, with cut ends deburred and protected
- Heat number and steel grade stenciled on each pipe end for site identification and traceability verification
- FOB, CIF, or DDP terms available with door-to-door logistics coordination for project sites
Initiating Your ERW Carbon Steel Round Pipe Inquiry
Submit your project specifications — including OD, wall thickness, length, steel grade, quantity, and destination port — to receive a detailed quotation with mill test certificate samples and production timeline. For non-standard dimensions or API 5L grades requiring special welding procedures, our engineering team provides technical clarification within 24 hours. Confirm certification requirements (CE/EN for EU, ASTM for North America, API for oil & gas) early in the inquiry stage to ensure documentation alignment with customs and inspection authorities.
Frequently Asked Questions
Q: How do Q235B, S235JR, and ASTM A36 compare for structural applications?
A: Q235B (Chinese GB standard), S235JR (European EN 10025), and ASTM A36 (US standard) are equivalent grades with similar yield strength requirements. All three are suitable for general structural framing, scaffolding, and non-pressure applications. Mill test certificates confirm chemical composition and mechanical properties per the specified standard.
Q: Can you provide full mill test certificates and third-party inspection?
A: Yes. Every ERW carbon steel round pipe shipment includes EN 10204 3.1 mill test certificates documenting chemical composition and mechanical properties by heat number. Third-party inspection from SGS, BV, or TÜV is available at any production stage — from raw material verification through final dimensional checks and surface treatment inspection.
Q: What is the MOQ for non-standard OD, wall thickness, or length?
A: MOQ depends on the specific dimension and steel grade requested. For standard sizes within our 14–1200mm OD and 1–50mm wall thickness range, we maintain inventory in Q235B and Q345B grades. Custom lengths beyond 6m or 12m are available with typical production lead times confirmed upon inquiry.
Q: When should I specify galvanized vs. 3LPE vs. black painted surface treatment?
A: Hot-dip galvanizing provides long-term corrosion protection for outdoor structural applications and coastal environments. 3LPE coating is specified for buried pipelines or aggressive soil conditions requiring barrier protection plus cathodic disbondment resistance. Black painted or oiled surfaces suit indoor structural use or temporary protection during fabrication and installation.
Q: How do you handle oversized pipe bundles and export documentation?
A: Professional loading plans optimize container utilization for 6m and 12m lengths, with edge protectors and steel strip bundling preventing transit damage. Export documentation includes packing list, bill of lading, certificate of origin, mill test certificates, and any required customs declarations for destination country clearance.
Request Your ERW Carbon Steel Round Pipe Quotation
Share your project drawings, specifications, steel grade requirements, and destination port to receive a detailed quotation with mill test certificate samples and production timeline.
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
