Description
Factory-Direct ERW Pipe Supply — 3 production lines running Q195 through Q345 and international equivalents with 20,000+ tons monthly output, eliminating trader markups on every container.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235/Q345 ERW Welded Round Steel Pipe |
| Product Type | ERW Welded Round Steel Pipe |
| Steel Grade | Q195, Q235, Q235B, Q345, S235JR, S275JR, S355JR, A53, St37, SS400 |
| Standard | GB/T 3091, GB/T 13912, BS 1387, ASTM A53, ASTM A500, ASTM A106, JIS G3466, EN 10219 |
| Section Shape | Round |
| Size Range | OD 10–1000 mm |
| Wall Thickness | 1–80 mm |
| Length | 1–12 m (standard 6 m / 6.4 m / 12 m) |
| Technique | ERW (Electric Resistance Welded) |
| Surface Treatment | Hot Rolled / Oiled / Non-Oiled |
| Tolerance | ±1% |
| Ends | Plain / Beveled |
| Processing Service | Bending, Cutting, Decoiling, Punching, Welding |
| Application | Fluid transport, hydraulic systems, structural frameworks, construction, machinery parts, greenhouse structures, fencing, curtain walls |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Infrastructure | Building frames, curtain wall supports, scaffolding uprights, fencing posts |
| Fluid & Energy Transport | Water supply mains, low-pressure gas lines, hydraulic cylinder bodies |
| Industrial Manufacturing | Machinery shafts, conveyor rollers, greenhouse arch structures |
| Agricultural & Commercial | Greenhouse structural frames, warehouse purlins, parking structure columns |
When Wall Tolerance Decides Whether a Fluid Line Passes Pressure Testing
A ±1% tolerance on ERW welded round steel pipe means the difference between a clean hydrostatic test and a rejected batch at the commissioning stage.
I have seen procurement teams order Q235 ERW pipes for water reticulation projects only to discover wall thickness variation exceeding the allowable band — the weld seam area thins out during forming, and without inline ultrasonic monitoring, those pipes ship looking perfect on the mill test certificate but fail under working pressure. Fragmented sourcing makes this worse: when the pipe, the flange, and the support bracket come from three different yards, nobody owns the tolerance chain. [NEED_CITE: ERW weld seam quality control standards for fluid transport pipes]
Matching OD and Wall Thickness to Structural Load Paths
When a Q345 ERW welded round steel pipe goes into a building frame or greenhouse arch, the outer diameter determines the moment of inertia while the wall thickness governs local buckling resistance. Our production lines cover OD 10–1000 mm with wall thickness from 1–80 mm, meaning a single purchase order can span purlin-size members and main column sections without splitting the procurement across suppliers. For greenhouse structures in coastal zones, we supply oiled or hot-rolled finish as a base, with galvanizing available as a secondary process — the ERW weld seam bonds cleanly with zinc coatings when the surface is properly prepared.
Engineering Compliance Across GB, ASTM, and EN Frameworks
Structural engineers specifying to EN 10219 for cold-formed hollow sections or ASTM A500 for structural tubing need documentation that traces each pipe back to its heat number. Our Q235B and Q345 pipes carry GB/T 3091 and GB/T 13912 certification, while S235JR through S355JR grades conform to EN 10219 requirements for European market compliance. Lloyd’s CE certification under EN 10210 and EN 10219 is available for projects requiring third-party factory production control verification. [NEED_CITE: EN 10219 cold-formed welded structural hollow sections compliance requirements] For North American specifiers, ASTM A53 and A500 grade mappings are documented in every mill test certificate, eliminating the guesswork at customs.
Understanding ERW Process and Steel Grade Selection
The ERW (Electric Resistance Welded) process forms round pipe from steel coil through continuous rolling and passes high-frequency current through the edges to create a forge weld — no filler metal, no slag, and a weld seam that, when properly controlled, matches the parent metal in strength. This makes ERW welded round steel pipe cost-effective for structural and low-to-medium pressure fluid applications where seamless pipe would be over-specified. Steel grade selection follows the load requirement: Q195 and S235JR serve light structural and fencing applications, while Q345 and S355JR provide higher yield strength for loaded frames and machinery components. The Q-series (Chinese GB standard), S-series (European EN standard), and ASTM A53/A500 (American) represent equivalent performance tiers — Q235B maps closely to S235JR and ASTM A53 Grade B, while Q345 aligns with S355JR and ASTM A572 Grade 50. [NEED_CITE: steel grade equivalence between GB Q-series and EN S-series standards] Surface treatment choice depends on the environment: hot-rolled finish suits indoor structural work, oiled surface provides short-term transit protection, and non-oiled finish is specified when the pipe will receive immediate painting or coating on site.
The Hidden Cost of Unverified Wall Thickness and Missing Heat Numbers
Pipes that arrive with wall thickness below the specified tolerance do not just fail inspection — they force the entire batch to be pulled from the installation, re-measured, and potentially replaced. On a project where Q345 ERW pipe was specified for structural columns, a negative tolerance deviation of even a fraction of a millimeter can reduce the load-bearing capacity below the engineer’s calculation, triggering a stop-work order until replacement material arrives. Worse, when mill test certificates lack heat number traceability or show chemical composition outside the grade specification, customs authorities in markets requiring CE or ISO documentation will hold the container regardless of the physical quality. [NEED_CITE: structural steel traceability requirements for project compliance] The cost is never just the pipe — it is the crane time, the crew standing idle, and the reputational damage with the end client.
Procurement Confidence from Mill Floor to Container Door
Every Q235/Q345 ERW welded round steel pipe we ship comes from our own three production lines in Jinan, meaning the price you see reflects factory-direct output with no trading company margin layered on top. Our in-house laboratory runs three-stage inspection — incoming coil chemistry verification, inline weld seam testing during ERW forming, and final dimensional and surface checks before bundling. We hold ISO 9001:2015 certification and Lloyd’s CE (EN 10210/EN 10219) with FPC documentation, and we arrange SGS or BV third-party inspection on request for buyers who need independent verification before the container is sealed. With over 2,800 specifications in ready stock, standard sizes ship within days while custom OD, wall thickness, or cut-to-length orders run on typical production lead times. Our export team handles container loading optimization for heavy pipe shipments, professional documentation, and customs clearance support across 50+ countries.
Documentation & Compliance
- Mill test certificate documenting Q235B or Q345 chemical composition, yield strength, and tensile properties per GB/T 3091 or GB/T 13912, traceable to heat number
- CE certificate under EN 10210 and EN 10219 for S235JR–S355JR grades, required for European structural steel compliance and customs clearance
- ISO 9001:2015 quality management certificate covering the full ERW production process from coil slitting to final bundling
- SGS or BV third-party inspection report available on request, covering dimensional verification, weld seam testing, and surface finish assessment before shipment
- Material traceability documentation linking each pipe to its heat number, coil batch, and production date for project audit requirements
- Full customs document package including packing list, bill of lading, and certificate of origin formatted for destination port requirements
Packaging, Loading & Delivery
- ERW welded round steel pipes bundled with steel strip ties and edge protectors, sized to match OD range and wall thickness to prevent deformation during transit
- Oiled surface pipes wrapped with waterproof paper or plastic sheeting to preserve the anti-rust coating during ocean freight to tropical and humid destinations
- Container loading plans optimized for 6 m, 6.4 m, and 12 m standard lengths, maximizing weight utilization within shipping container limits for heavy-wall Q345 sections
- Cut-to-length service available for 1–12 m requirements, with beveled or plain ends prepared per order specification before bundling
- Heat number and steel grade stenciled on each pipe bundle for site identification and traceability verification during installation
- FOB, CIF, and DDP shipping terms supported with professional export documentation and real-time tracking from Jinan inland depot to destination port
Start Your Procurement with Verified Specifications
Submit your required OD, wall thickness, steel grade, quantity, and destination port — we respond within hours with factory-direct pricing, available stock confirmation, and mill test certificate samples. For non-standard dimensions or custom cut-to-length requirements, our technical team provides feasibility feedback and production timelines based on current line scheduling. Confirm your certification needs (CE, ISO, SGS/BV inspection) at inquiry stage so documentation is prepared alongside production rather than as an afterthought.
Request Factory-Direct Pricing and Mill Test Certificates
Send your specification sheet via email or WhatsApp to receive a detailed quotation with volume pricing, delivery schedule, and sample mill test certificates for your specified steel grade.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.sdxinjiyuan.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@sdxinjiyuan.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
