Description
Factory-Direct ERW Welded Round Steel Pipe — Every batch tested in our own physical and chemical laboratory before shipment, with full traceability from raw material to finished pipe.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q195-Q345 ERW Welded Round Steel Pipe |
| Product Type | ERW Welded Round Steel Pipe |
| Steel Grade | Q195, Q235, Q345, 10#, 20#, 45#, 16Mn, ASTM A53, A106, A252, A369, ST35, ST52, Grade A/B/C |
| Standard | API 5L, ASTM A53, ASTM A106, ASTM A252, ASTM A671, ASTM A450, ASME B36.10M, BS EN 10219, BS EN 10296, BS 1387, BS 6323, BS 6363, GB/T 3091, GB/T 13793, GB/T 9711, GB/T 8163 |
| Section Shape | Round |
| Size Range | Outer Diameter 10–700 mm |
| Wall Thickness | Cold rolled 1–4.0 mm; Hot rolled 4–20 mm |
| Length | 1–12 m |
| Technique | ERW / Hot Rolled / Cold Rolled / Cold Drawn |
| Surface Treatment | Hot Rolled / Cold Rolled / Oiled / Non-oiled |
| Tolerance | ±1% |
| Ends | Plain / Beveled (per standard) |
| Application | Fluid transport, structural frameworks, construction scaffolding, boiler systems, hydraulic and drill applications, chemical fertilizer pipelines |
| MOQ | 28 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| EPC Contractors & Construction | Structural frameworks for industrial buildings, scaffolding systems, piling foundations per ASTM A252 |
| Machinery & Industrial Manufacturing | Hydraulic cylinder bodies, fluid conveyance lines, boiler heat-exchange tubes per A106 and ST35–ST52 |
| Oil, Gas & Chemical | Pipeline networks for water, gas, and oil transport meeting API 5L and GB/T 9711 |
| Infrastructure & Civil Engineering | Bridge support columns, conveyor structures, drainage and irrigation systems |
Where Negative Tolerance Turns a Pipe Order Into a Project Delay
Every millimeter of wall-thickness deviation compounds across hundreds of tons into structural risk and customs rejection.
I have watched an entire container of welded carbon steel pipes get rejected at a Southeast Asian port because the actual weight fell well below theoretical calculations. The pipes failed on-site pressure tests. The client lost weeks of schedule and paid for return freight on top. That kind of failure does not come from bad intentions — it comes from suppliers who skip incoming inspection and ship without verifying tolerance against the declared standard. When you source an ERW welded round steel pipe supplier who runs every heat through an in-house lab, that scenario stays on paper instead of arriving at your job site. [NEED_CITE: EN 10219 dimensional tolerance requirements for welded hollow sections]
Matching Pipe Dimensions to Structural Load Paths
An ERW welded round steel pipe in the OD 10–700 mm range covers everything from small-bore hydraulic lines to large-diameter piling columns. For structural frameworks and scaffolding, Q235 and Q345 grades provide the yield strength needed for load-bearing frames while remaining weldable on-site with standard procedures. When the project demands fluid conveyance under pressure — boiler feed lines or process piping — grades like 20# and ST35–ST52 meet the elevated-temperature and tensile requirements of ASTM A106 and corresponding EN specifications. The ±1% tolerance on wall thickness means the load calculations your engineer signed off on actually match what arrives in the bundle.
Engineering Compliance Across Destination Markets
Different project specifications call for different standard frameworks, and mixing them up creates delays that no amount of expedited shipping can fix. European structural projects require CE marking under EN 10210 or EN 10219, and customs authorities in EU member states will hold shipments without valid certification documentation. [NEED_CITE: CE marking requirements for structural steel hollow sections under EN 10210] North American infrastructure tenders typically specify ASTM A53 or A500, while oil and gas pipelines in the Middle East and Southeast Asia reference API 5L. Our production lines cover all these standards within a single order, and our in-house laboratory issues mill test certificates that satisfy each framework’s traceability requirements. For Southeast Asian government projects, Singapore FPC certification ensures smooth import clearance without additional testing at the destination port.
Understanding Steel Grade Selection for ERW Pipe
The Q-series (Q195, Q235, Q345) follows the Chinese GB system where the number indicates minimum yield strength in MPa — Q345 delivers higher load capacity than Q235, making it suitable for heavier structural applications. ASTM A53 covers general-purpose welded and seamless pipe for mechanical and pressure use, while A106 specifies seamless carbon steel pipe for high-temperature service in boiler and superheater applications. ST35 and ST52, from the German DIN system, are commonly specified for hydraulic cylinders and precision machined components where tight dimensional control matters. The ERW welding process itself produces a longitudinal weld seam through high-frequency electric resistance welding, which offers cost advantages over seamless pipe at smaller diameters while maintaining consistent weld quality through inline ultrasonic inspection. [NEED_CITE: steel grade equivalence mapping between GB, ASTM, and EN systems] Cold rolled ERW pipe in the 1–4.0 mm wall range provides tighter surface finish and dimensional accuracy for precision applications, while hot rolled variants in the 4–20 mm range serve structural and heavy-duty fluid transport needs.
The Hidden Cost of Unverified Pipe Specifications
Ordering ERW welded round steel pipe without confirmed mill test certificates creates a cascade of risks that surface only when the material reaches the project site. Pipes with undocumented chemical composition may fail weldability tests, forcing rework or replacement of entire sections. Wall thickness below declared tolerance reduces pressure ratings and structural load capacity, creating safety liabilities that no amount of post-hoc documentation can resolve. Missing or incomplete CE or ISO certificates trigger customs holds that delay project timelines by weeks — and the demurrage charges at port often exceed the original price difference between a verified supplier and an unverified one. [NEED_CITE: consequences of non-compliant steel imports on project timelines]
Why Project Procurement Teams Choose Our Factory
We operate three dedicated production lines covering over 2,800 specifications in square, rectangular, and round profiles, with wall thickness reaching 20 mm for hot rolled ERW pipe. Our factory holds 41 invention patents, including proprietary sharp-corner rectangular tube technology that addresses dimensional gaps in the global market. Every production batch passes through our in-house physical and chemical laboratory for incoming material verification, in-process monitoring, and final inspection before shipment — the same lab that caught the tolerance issue I witnessed years ago. We hold CE certification under EN 10210/10219, ISO 9001:2015, Singapore FPC, and accept third-party inspection through SGS and BV. Our export experience spans 50+ countries across the EU, North America, India, Southeast Asia, and the Middle East, with professional loading plans that optimize container weight distribution for heavy pipe shipments.
Documentation & Compliance
- Mill test certificate documenting Q235/Q345 chemical composition and mechanical properties per GB/T 3091 or corresponding ASTM standard for each heat number
- CE certificate under EN 10210/EN 10219 for structural hollow sections destined for European Union markets
- ISO 9001:2015 quality management system certificate covering the full production process from raw material to finished pipe
- SGS or BV third-party inspection report available upon request for projects requiring independent verification
- Full material traceability by heat number linking each pipe bundle to its mill test certificate and production batch record
- Complete customs documentation package including packing list, bill of lading, and certificate of origin for smooth import clearance
Packaging, Loading & Delivery
- ERW welded round steel pipes bundled with steel strips and seaworthy packaging, with edge protectors for oiled surface finishes to prevent coating damage during ocean transit
- Surface protection selected per order specification: oiled finish for corrosion prevention during storage and transit, or non-oiled bare finish for projects requiring immediate painting or galvanizing upon arrival
- Container loading optimized for the 10–700 mm OD range, with nested smaller-diameter pipes inside larger ones to maximize weight utilization within the 28-ton MOQ threshold
- Cut-to-length service available within the 1–12 m range, with bundles clearly marked by length, steel grade, and heat number for rapid identification at the project site
- Heat number and steel grade stenciled on each pipe end, with bundle tags matching the mill test certificate for full traceability upon delivery
- Shipping terms available including FOB, CIF, and DDP, with professional logistics coordination for door-to-door delivery to 50+ countries
Starting Your Procurement Process
Submit your specifications including outer diameter, wall thickness, steel grade, quantity, and destination port to receive a detailed quotation with delivery timeline and applicable certification documentation. For non-standard dimensions or custom cut-to-length requirements, our technical team will provide a feasibility assessment and production schedule. All inquiries receive a response within 12 hours, including preliminary pricing and mill test certificate samples from recent production batches.
Frequently Asked Questions
Q: How do Q235 and Q345 steel grades map to ASTM and EN equivalents?
A: Q235 generally corresponds to ASTM A36 and EN S235 in terms of yield strength range, while Q345 aligns with ASTM A572 Grade 50 and EN S355. We provide detailed chemical composition comparison in our mill test certificates to support your material approval process.
Q: Do your CE and ISO certificates support customs clearance in the EU and Southeast Asia?
A: Yes. Our CE certification under EN 10210/10219 satisfies European structural steel import requirements, and our Singapore FPC certification is specifically recognized for Southeast Asian government and infrastructure projects. ISO 9001:2015 covers our quality management system across all export markets.
Q: Can you produce non-standard outer diameters or wall thicknesses outside your listed range?
A: We maintain over 2,800 specifications in our production system and can accommodate custom non-standard dimensions based on your project requirements. Contact our technical team with your specific dimensions for a feasibility assessment and production timeline.
Q: What quality testing is performed before shipment, and can I arrange third-party inspection?
A: Every batch undergoes incoming material inspection, in-process monitoring, and final inspection in our in-house physical and chemical laboratory, with full mill test certificates provided. We also accept third-party inspection through SGS or BV at your request, with inspection reports included in the shipping documentation package.
Q: What shipping terms do you support, and how do you handle container loading for heavy pipes?
A: We offer FOB, CIF, and DDP shipping terms with professional loading plans that optimize container weight distribution. For ERW welded round steel pipe orders, we nest smaller-diameter pipes inside larger ones to maximize payload within container weight limits, and all bundles are secured with steel strips and edge protectors for safe ocean transit.
Get Your ERW Welded Round Steel Pipe Quote with Full Certification
Submit your specifications, steel grade, and destination port to receive pricing and mill test certificate documentation within 12 hours.
Contact: Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@sdxjysteel.com
Website: www.sdxjysteel.com
