Description
Factory-Direct ERW Pipe Supply — 3 production lines running Q235 Q355 ERW round steel pipe in OD 10–700 mm with original mill test certificates on every heat.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235 Q355 ERW Round Steel Pipe |
| Product Type | ERW Round Steel Pipe |
| Steel Grade | Q195, Q235, Q355, SS400, 10#, 45#, 16Mn, A53, A369, ST35, ST52, Grade A, Grade B, Grade C |
| Standard | API 5L, ASTM A53, ASTM A106, ASTM A252, ASTM A500, ASTM A671, ASTM A450, ASME B36.10M, BS 1387, BS EN 10219, BS EN 10296, BS 6323, BS 6363, GB/T 3091, GB/T 13793, GB/T 9711, JIS G3466 |
| Section Shape | Round |
| Outer Diameter | 10–700 mm |
| Wall Thickness (Cold Rolled) | 1–4.0 mm |
| Wall Thickness (Hot Rolled) | 4–20 mm |
| Length | 1–12 m |
| Technique | Hot Rolled / Cold Rolled / Cold Drawn |
| Surface Treatment | Hot Rolled / Zinc Coated (200–700 g/sqm) / Slightly Oiled |
| Tolerance | ±1% |
| Ends | Plain / Beveled (per standard) |
| Application | Fluid transport / Structural / Construction / Boiler / Hydraulic / Drill pipe / Scaffolding / Machinery |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Infrastructure | Structural columns, scaffolding tubes, piling casings, building frames |
| Fluid & Energy Transmission | Water supply lines, gas distribution pipes, oil transport, boiler tubes, hydraulic systems |
| Industrial & Machinery | Equipment frames, drill pipes, chemical fertilizer pipelines, conveyor structures |
What Wall-Thickness Tolerance Costs on a Q235 Q355 ERW Round Steel Pipe Order
A ±1% tolerance on wall thickness is the difference between passing SGS at destination and losing an entire container on site.
I have watched project buyers receive Q235 ERW pipes with mill certificates that looked clean, only to find actual wall thickness dropping well below the specified 2.5 mm when measured at the weld seam. The whole shipment gets rejected, the project timeline shifts by weeks, and the cost of replacement freight dwarfs the original price difference between suppliers. For a Q235 Q355 ERW round steel pipe supplier running three production lines simultaneously, maintaining consistent ±1% dimensional tolerance across OD 10–700 mm requires in-house ultrasonic measurement on every batch, not spot checks. [NEED_CITE: EN 10219 dimensional tolerance requirements for cold-formed welded hollow sections]
Matching ERW Round Pipe to Structural and Fluid Applications
A Q235 Q355 ERW round steel pipe in OD 10–700 mm covers the full spectrum from small-bore hydraulic lines to large-diameter piling casings. Cold-rolled walls from 1–4.0 mm serve precision applications where weight and dimensional accuracy matter, while hot-rolled walls from 4–20 mm handle structural loads in building frames and scaffolding. Surface treatment selection — hot rolled black for indoor structural use, zinc coated at 200–700 g/sqm for outdoor or buried exposure, slightly oiled for temporary corrosion protection during transit — directly determines service life in corrosive environments. Our three production lines allow mixed-size container loading, so a single order can supply both 21.3 mm scaffolding tubes and 323.9 mm structural columns without splitting shipments across multiple suppliers.
Engineering Compliance and Certification Requirements
Structural applications demand conformity with EN 1993 or AISC design codes, which reference material standards like EN 10219 for cold-formed welded sections or ASTM A500 for structural tubing. A Q235 Q355 ERW round steel pipe conforming to GB/T 3091 or GB/T 13793 carries the mill test certificate required for Chinese-origin projects, while equivalent grades mapped to ASTM A53 or BS EN 10219 satisfy international specification sheets. European buyers need CE certification under EN 10210/10219 and Factory Production Control documentation to clear customs without delay. [NEED_CITE: CE marking requirements for structural steel hollow sections under EN 10210] Length customization from 1–12 m with plain or beveled ends reduces on-site cutting waste and supports optimized container loading for 20ft and 40ft containers.
Steel Grade Selection and ERW Process Fundamentals
Q235 and Q355 represent the two most widely specified structural grades in the Chinese standard system, with Q355 offering higher yield strength for load-bearing applications. When international projects require equivalent grades, Q235 maps to S235JR under EN 10219 or Grade A under ASTM A53, while Q355 corresponds to S355JR or ASTM A572 Grade 50 — a Q235 Q355 ERW round steel pipe supplier must provide cross-standard equivalence documentation to avoid specification mismatches. The ERW process forms the pipe from coiled steel strip, welding the longitudinal seam through high-frequency electric resistance, which produces a cost-effective solution for low-to-medium pressure applications compared to seamless alternatives. Surface treatment options reflect end-use conditions: hot rolled black finish suits indoor structural work, zinc coating at 200–700 g/sqm provides sacrificial protection for outdoor or buried service, and slight oiling prevents rust during ocean transit without affecting weldability. Wall thickness tolerance of ±1% ensures that theoretical weight calculations match actual delivered weight, preventing disputes over short-weight claims at destination.
Hidden Costs of Incorrect Grade or Missing Certification
Specifying Q355 but receiving Q235 due to unclear grade marking reduces structural load capacity and fails engineering inspection under EN 1993 or AISC review. Missing mill test certificates or absent CE marking for European shipments triggers customs holds, demurrage charges, and potential rejection at the port of entry. [NEED_CITE: material traceability requirements under EN 10204 for steel products] Negative tolerance abuse — where actual wall thickness falls below the minimum specified — compromises pressure ratings in fluid transport and load-bearing capacity in structural frames, creating safety liabilities that surface only after installation.
Procurement Confidence from Factory-Direct Supply
As a factory-direct Q235 Q355 ERW round steel pipe supplier operating three production lines with monthly capacity exceeding 20,000 tons, we eliminate middleman markups and provide transparent pricing tied to raw material indices. Every batch ships with original mill test certificates documenting chemical composition and mechanical properties per the specified standard, verified by our in-house laboratory with three-stage inspection. Third-party inspection by SGS or BV is available on request for buyers requiring independent verification. Our inventory covers 2,800+ specifications across round, square, rectangular, and section steel, enabling consolidated container loading that reduces freight costs for multi-product orders. Professional export documentation handling ensures customs clearance readiness for destinations across 50+ countries.
Documentation & Compliance
- Mill test certificate documenting Q235 or Q355 chemical composition and mechanical properties per GB/T 3091 or GB/T 13793, with heat number traceability
- CE certificate under EN 10210/EN 10219 for structural hollow sections destined for European Union markets
- ISO 9001:2015 quality management certificate covering the full production and inspection process
- SGS or BV third-party inspection report available on request, verifying wall thickness, dimensional tolerance, and surface coating weight
- Material traceability by heat number linking each pipe to its original coil and production batch
- Customs documents including packing list, bill of lading, and certificate of origin formatted for destination port requirements
Packaging, Loading & Delivery
- Q235 Q355 ERW round steel pipes bundled with steel strips and edge protectors to preserve surface treatment during ocean transit
- Zinc-coated pipes wrapped with waterproof paper and plastic film to prevent white rust formation in humid container environments
- Mixed-size container loading optimized for 20ft and 40ft units, combining small-bore and large-diameter pipes to maximize payload within weight limits
- Length customization from 1–12 m supports standard container dimensions, reducing cutting waste and on-site adjustments
- Heat number and steel grade stenciled on each pipe end for on-site identification and traceability verification
- FOB, CIF, and DDP trade terms available with professional logistics coordination from Jinan port to destination
Requesting a Quotation for Your ERW Pipe Requirements
Submit your specification sheet including outer diameter, wall thickness, steel grade, quantity, and destination port to receive a competitive bulk quotation with volume discount tiers. We provide original mill test certificates and cross-standard grade equivalence tables within the initial response, enabling engineering teams to verify compliance before committing to production. Non-standard dimensions and custom lengths are available with typical production lead times confirmed upon order placement.
Frequently Asked Questions
Q: How do Q235 and Q355 map to international standards like ASTM A53 or EN 10219?
A: Q235 corresponds to S235JR under EN 10219 and Grade A under ASTM A53, while Q355 maps to S355JR under EN 10219 and Grade 50 under ASTM A572. We provide equivalence documentation with every quotation to ensure your specification is met.
Q: Can you provide mill test certificates and arrange third-party inspection?
A: Yes, every shipment includes original mill test certificates documenting chemical composition and mechanical properties. SGS or BV third-party inspection is available on request for independent verification of dimensions, coating weight, and material properties.
Q: What is the MOQ for non-standard outer diameter or wall thickness?
A: Our flexible MOQ starts from 1 ton for trial orders, with custom dimensions available across the OD 10–700 mm and wall thickness 1–20 mm range. Lead times for non-standard specifications are confirmed upon order placement.
Q: When should I choose galvanized versus hot rolled black or oiled finish?
A: Zinc coating at 200–700 g/sqm is specified for outdoor or buried applications requiring long-term corrosion protection. Hot rolled black finish suits indoor structural use, while slight oiling provides temporary rust prevention during transit without affecting weldability.
Q: How do you optimize container loading for round pipes of mixed sizes?
A: We combine small-bore and large-diameter pipes in nested or side-by-side configurations to maximize payload within container weight limits. Length customization to 1–12 m ensures pipes fit standard 20ft and 40ft container dimensions without overhang.
Get Your Q235 Q355 ERW Round Steel Pipe Quote with Mill Test Certificates
Send your specification requirements via email or WhatsApp to receive factory-direct pricing, grade equivalence tables, and delivery confirmation within 12 hours.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.sdxinjiyuan.com
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@sdxinjiyuan.com
