Description
Factory-Direct Seamless Pipe — 2,800+ specifications in stock, mill to site
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Seamless Round Steel Pipe (Carbon Steel Grades 10#-45#) |
| Product Type | Seamless Round Steel Pipe / Circular Hollow Section |
| Steel Grade | 10#, 20#, 35#, 45#, Q235, Q345, Q195, Q215, Q345C, Q345A, 16Mn, 40Cr, 15CrMo, 45Mn2 |
| Standard | API, ASTM (A53A/A53B/A106B/A178C, API 5L), BS, DIN, GB, JIS |
| Section Shape | Round |
| Outer Diameter | 21.3–1420 mm |
| Wall Thickness | 2.11–300 mm |
| Length | 6 m / 6.4 m / 12 m |
| Technique | Seamless (Cold Rolled) |
| Surface Treatment | Slightly Oiled / Cold Rolled |
| Tolerance | ±1% |
| Ends | Plain / Beveled (as required) |
| Application | Fluid transport, Boiler, Drill pipe, Hydraulic pipe, Gas pipe, Oil pipe, Chemical fertilizer pipe, Structure pipe, Machinery parts, Automobile/tractor stress parts, Construction, Accessorize |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Oil & Gas / Petrochemical | High-pressure fluid transport pipelines, drill pipe, gas distribution networks |
| Industrial Infrastructure | Structural columns, truss members, platform supports, conveyor frames |
| Boiler & Mechanical Engineering | Heat exchanger tubes, hydraulic cylinders, machinery shafts, automobile stress components |
| Construction & EPC Projects | Building frames, scaffold uprights, piling casings, accessorie fittings |
What Material Traceability Gaps Cost on a Seamless Pipe Order
Missing heat-number documentation turns a routine delivery into a customs hold or a failed weld procedure qualification.
When procurement teams source seamless round steel pipe from overseas, the most frequent failure is not the pipe itself — it is the paperwork gap between the mill and the buyer. Third-party traders blend heats, re-stamp markings, or supply partial MTCs that do not cover every pipe in the bundle. On projects governed by API 5L or ASTM A106, inspectors reject entire shipments when chemical composition cannot be traced back to the original billet. [NEED_CITE: material traceability requirements in API 5L and ASTM A106] The cost is not just the replacement steel — it is the crane time, the welding crew idle, and the re-certification cycle that pushes the critical path by weeks.
Matching Grade Selection to Pressure and Structural Demands
A Seamless Round Steel Pipe supplier China must understand that grade selection is not a catalog exercise. For high-pressure oil and gas lines, 20# and 15CrMo deliver the creep resistance and weldability required by ASTM A106 and API 5L environments. For structural frameworks under EN 1993 or AISC load combinations, Q345 and Q355 series provide the yield plateau that engineers specify for columns and trusses. Our cold-rolled seamless process holds ±1% tolerance across OD 21.3–1420mm and WT 2.11–300mm, which means the hydraulic cylinder bore you machine on-site stays within design clearance — no shimming, no re-boring.
Engineering Code Compliance and Certification Pathways
Structural hollow sections destined for EU markets must conform to EN 10210 or EN 10219, with CE marking and factory production control audits. North American projects require ASTM A53 or A500 compliance, often with supplementary Charpy impact testing at sub-zero temperatures. [NEED_CITE: EN 10219 cold-formed hollow section requirements] Seamless carbon steel pipe for pressure applications follows API 5L PSL1/PSL2 or ASTM A106 Grade B/C, with hydrostatic testing and non-destructive examination per clause. We supply full documentation packages — MTC per EN 10204 3.1/3.2, WPS/PQR for downstream welding, dimensional inspection reports, and coating thickness certificates — so that your QA manager signs off before the container leaves Jinan.
Understanding Cold-Rolled Seamless Process and Grade Coverage
The cold-rolled seamless method produces tighter dimensional accuracy and smoother surface finish compared to hot-rolled alternatives, making it suitable for hydraulic systems, precision machinery parts, and automotive components where surface defects initiate fatigue cracks. Carbon steel grades 10# through 45# offer a yield strength gradient — 10# for deep-drawn fittings, 20# for general pressure piping, 35# and 45# for machined shafts and high-stress structural connections. Alloy additions like 40Cr and 15CrMo introduce chromium for hardenability and high-temperature service. The Q-series (Q235, Q345) maps to structural applications where weldability and formability take priority over tensile strength. [NEED_CITE: steel grade equivalence between EN and ASTM standards]
The Hidden Cost of Wrong Grade or Unverified Tolerance
Specifying Q235 when the drawing calls for Q345 does not show up until the first weld cracks under load or the column deflects beyond L/360. Negative tolerance stacking — where every pipe in a 50-ton order sits at the lower limit of wall thickness — reduces the theoretical weight and the actual load-bearing capacity simultaneously. Buyers who accept “mill standard” tolerance without verifying ±1% on every heat risk structural rejection during third-party inspection. [NEED_CITE: tolerance stacking effects on structural hollow section capacity] The rework cost — cutting out welded assemblies, re-ordering, re-welding, re-inspecting — typically exceeds the original pipe price by a factor of three.
Why Project Teams Specify XJY Structure for Seamless Pipe
We operate our own steel mill with three production lines and over 2,800 specifications in raw material inventory, which means we control the billet-to-pipe chain without outsourcing to third-party traders. Every Seamless Round Steel Pipe we ship carries a unique heat number etched into the pipe end, linked to a mill test certificate that documents chemical composition, tensile properties, and impact energy for that specific melt. Our in-house fabrication workshop handles CNC cutting, beveling, drilling, bending, and welding per AWS/EN certified procedures — so if your project needs pre-fab assemblies rather than raw pipe lengths, we deliver ready-to-install components. Third-party inspection through SGS, BV, or TUV is arranged before shipment, and our logistics team plans oversized cargo loading for 12-meter lengths and heavy-wall sections up to 300mm WT.
Documentation & Compliance
- Mill Test Certificate documenting 10#–45# carbon steel chemical composition and mechanical properties per ASTM A106 / API 5L, with heat-number traceability from billet to finished pipe
- CE certificate for EN 10210 / EN 10219 structural hollow sections, required for EU market customs clearance and site acceptance
- ISO 9001 quality management certificate covering the full production chain from raw material procurement through final dimensional inspection
- SGS or BV third-party inspection report verifying OD, WT, length, surface quality, and end preparation before container sealing
- Material traceability register linking each pipe bundle to its original heat number, with test reports available for every heat in the shipment
- Export customs documentation including packing list, bill of lading, certificate of origin, and commercial invoice formatted for destination-country clearance
Packaging, Loading & Delivery
- Cold-rolled seamless pipes bundled with steel strips and edge protectors to preserve the oiled surface finish and prevent OD scratches during ocean transit
- 6-meter and 12-meter lengths loaded in dedicated containers with wooden chocks and lashing belts to prevent longitudinal shifting under heavy-wall sections (WT up to 300mm)
- Beveled-end pipes capped with plastic protectors to maintain weld-prep geometry and prevent moisture ingress during storage at the job site
- Heat number and steel grade stenciled on each pipe end and bundle tag, matching the mill test certificate for on-site verification by QA inspectors
- FOB Jinan/Qingdao, CIF destination port, or DDP door-to-door delivery arranged for project sites across the Middle East, Southeast Asia, Africa, and South America
- Custom cutting to non-standard lengths (e.g., 6.4-meter for specific container optimization) available upon request, with kerf tolerance held within ±5mm
How to Initiate Your Seamless Pipe Inquiry
Submit your project drawings (PDF or DWG), steel grade requirements, OD/WT dimensions, applicable standard (API 5L / ASTM A106 / EN 10210), and destination port. We return a detailed quotation within 24 hours — including material cost, fabrication charges if pre-fab assemblies are required, coating and packing specifications, and a production schedule tied to your project timeline. Our engineering team reviews shop drawings and confirms material availability from our 2,800+ specification inventory before you commit to a deposit.
Frequently Asked Questions
Q: How do Chinese steel grades like 20# and Q345 map to ASTM or EN equivalents?
A: Grade 20# carbon steel aligns with ASTM A106 Grade B for high-temperature pressure service, while Q345 structural steel corresponds to S355JR/S355J2 under EN 10025 or ASTM A572 Grade 50 for structural applications. We provide a full equivalence table with your inquiry response, covering chemical composition and mechanical property comparisons across GB, ASTM, EN, and JIS standards.
Q: Can you arrange third-party inspection before shipment?
A: Yes. We coordinate pre-shipment inspection through SGS, BV, or TUV at our facility. The inspection covers dimensional verification (OD, WT, length), visual surface quality, end preparation, and review of mill test certificates. You receive the inspection report before the container is sealed.
Q: What is the minimum order quantity for non-standard dimensions?
A: The standard MOQ is 1 Ton. For non-standard OD/WT combinations or custom lengths outside our 6m / 6.4m / 12m range, we review production feasibility based on our mill’s rolling schedule and provide a tailored lead time and pricing structure.
Q: What surface treatment options are available for offshore or corrosive environments?
A: Standard delivery is slightly oiled for indoor storage and short-term corrosion protection. For offshore or buried applications, we offer 3PE anti-corrosion coating, hot-dip galvanizing, or epoxy painting per project specification. Each coating type comes with thickness measurement reports and adhesion test results.
Q: How do you handle shipping for heavy-wall or large-diameter seamless pipes?
A: Pipes with OD above 600mm or WT exceeding 50mm exceed standard container weight limits. We plan specialized flat-rack or open-top container loading, or break-bulk shipping for project cargo. Our logistics team provides loading diagrams, lashing calculations, and stowage plans to ensure safe transit and efficient unloading at your site.
Get Your Seamless Pipe Quotation with Full Mill Documentation
Send your specifications, steel grade, and quantity to receive a detailed quotation and sample mill test certificate within 24 hours.
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
