Description
Factory-Direct Seamless Pipe — 2,800+ specifications in stock from our own mill, eliminating trader markups and certification gaps.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | 20# 45# Seamless Carbon Steel Structure Pipe |
| Product Type | Seamless Steel Pipe |
| Steel Grade | 20#, 45#, ASTM A106 Grade A/B |
| Standard | ASTM A106, API 5CT, API 5L, JIS, BS, DIN |
| Section Shape | Round |
| Outer Diameter | 10–609 mm |
| Wall Thickness | 1.65–59.54 mm |
| Length | 5.8–12 m (standard export length) |
| Technique | Hot Rolled / Cold Rolled / Cold Drawn |
| Surface Treatment | Hot Rolled / Oiled / Non-oiled |
| Tolerance | ±5% / ±1% |
| Ends | Plain / Beveled |
| Application | Fluid transportation / Machinery parts / Structural components / Boiler / Hydraulic / Gas & Oil pipeline / Chemical fertilizer / Drill pipe |
| Invoicing | By Theoretical Weight |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| EPC Industrial Projects | Plant structure frames, boiler support columns, machinery base supports |
| Oil & Gas Infrastructure | Transmission pipelines, gathering lines, process piping in refineries |
| Power Generation | Boiler tubes, superheater elements, steam piping systems |
| Mechanical Engineering | Hydraulic cylinder barrels, machining blanks, shaft sleeves |
| Construction & Infrastructure | Structural columns, truss members, bridge handrail posts |
What Negative Tolerance Costs When You Order an ASTM A106 Seamless Carbon Steel Structure Pipe
A 0.4 mm wall shortfall on a 6-meter structural member forces full recalculation of load-bearing capacity.
Overseas buyers sourcing seamless structure pipe from traders rather than integrated producers face a recurring problem: the mill test certificate says one thing, but the third-party inspection at destination reveals another. Wall thickness drifts beyond acceptable tolerance, chemistry ranges shift, and the material traceability chain breaks somewhere between the original billet and the final bundle. On a boiler support frame or a hydraulic manifold, those fractions of a millimeter determine whether the structure passes load testing or gets rejected at site acceptance. [NEED_CITE: ASTM A106 dimensional tolerance requirements for seamless pipe]
Matching Wall Thickness Range to Structural and Pressure Applications
The 1.65–59.54 mm wall thickness range across OD 10–609 mm covers everything from small-bore instrument lines to heavy-wall pressure vessels and structural columns. Hot-rolled process handles the thicker walls economically, while cold-drawn delivers the tighter ±1% tolerance needed for machining fits and hydraulic cylinder applications. Our own mill produces the raw billets, then our fabrication division cuts, welds, and assembles these ASTM A106 seamless carbon steel structure pipe into finished structural frames — so the material certification stays intact from billet to final assembly.
Engineering Compliance for International Structural Projects
Structural applications in the EU require EN 1090 execution class documentation; Middle East EPC projects typically specify API or ASTM standards with third-party inspection at the mill. The 20# grade maps to ASTM A106 Grade B for most pressure and structural applications, while 45# serves higher-strength machining and mechanical component requirements. Beveled ends ready for field welding, plain ends for coupling or machining — we prepare the ends to your fabrication sequence. Third-party inspection by SGS, BV, or TÜV is available before shipment to close the documentation loop for customs and site acceptance. [NEED_CITE: EN 1090 structural steel fabrication compliance requirements]
Understanding Grade Selection: 20# vs 45# vs ASTM A106
The 20# grade is a low-carbon manganese steel offering good weldability and formability for structural frames and pressure piping where moderate strength suffices. The 45# grade increases carbon content for higher tensile strength, suited to machined components, shafts, and hydraulic parts where surface hardness matters. ASTM A106 Grade A and B provide the equivalent international specification for high-temperature service, with Grade B being the most commonly specified for process piping and structural applications in the Middle East and Southeast Asia. Hot-rolled finish delivers the as-produced surface suitable for downstream coating or painting, while oiled condition protects against transit corrosion during ocean shipment. The cold-drawn process achieves tighter dimensional control for applications requiring precise fit-up in hydraulic systems or machined assemblies.
The Hidden Cost of Unverified Material Certification
When a trader supplies seamless pipe without direct mill traceability, the heat number on the certificate may not match the physical markings on the tube. At destination, the client’s third-party inspector flags the discrepancy — and the entire batch faces rejection or re-inspection at the buyer’s cost. On a recent project, a 0.4 mm wall thickness deviation on a 6-meter structural member meant the entire load-bearing calculation had to be redone by the project engineer. Delays cascade: customs holds, site acceptance failures, re-procurement lead times. With our vertically integrated mill, every ASTM A106 seamless carbon steel structure pipe carries full heat-number traceability back to the original billet, verified by our in-house laboratory and available for third-party audit before loading. [NEED_CITE: material traceability requirements for pressure piping per ASME B31.3]
Why Source Your ASTM A106 Seamless Carbon Steel Structure Pipe From Us
Our own steel production facility operates three production lines with over 2,800 stock specifications — meaning the seamless pipe you order comes from our mill, not a broker’s warehouse. The in-house metallurgical laboratory performs PMI, tensile testing, impact testing, and hydrostatic verification before any bundle leaves the shop. For projects requiring downstream fabrication, our structural steel division handles cutting, welding, drilling, and assembly using the same material certification — no gaps in the traceability chain. Certified welding procedures per AWS and EN standards, qualified welders, and complete quality documentation packages including WPS, PQR, weld maps, and dimensional inspection reports ship with every order. We have delivered structural steel packages to EPC projects across the EU, Middle East, Southeast Asia, and Africa, with professional loading plans for oversized components and complete export documentation for customs clearance.
Documentation & Compliance
- Mill Test Certificate per EN 10204 3.1/3.2 documenting 20# and 45# chemical composition, tensile strength, and elongation per ASTM A106
- Third-party inspection reports from SGS, BV, or TÜV covering dimensional verification, visual inspection, and NDT results before shipment
- ISO 9001 quality management system certificate covering the full production process from billet to finished ASTM A106 seamless carbon steel structure pipe
- Material traceability by heat number linked to original billet casting records and chemical analysis
- Export customs documentation including packing list, bill of lading, and certificate of origin for destination clearance
- Welding procedure specifications and welder qualification records for any downstream fabrication performed at our facility
Packaging, Loading & Delivery
- Seamless pipes bundled with steel strips and edge protectors, surface oiled to prevent transit corrosion during ocean shipment of 20# and 45# grades
- Standard export length 5.8–12 m loaded in 20ft or 40ft containers with optimized stowage plans maximizing payload for OD 10–609 mm range
- Beveled or plain ends protected with plastic caps to prevent damage during handling and transport to site
- Heat number and steel grade stenciled on each pipe for on-site identification and traceability verification
- FOB, CIF, and DDP delivery terms available with professional loading supervision for heavy-wall ASTM A106 seamless carbon steel structure pipe orders
- Custom cut-to-length and end preparation services available for fabrication-ready delivery to project site
Start Your ASTM A106 Seamless Carbon Steel Structure Pipe Inquiry
Share your project drawings, required specifications, steel grades, and destination port — we respond within 24 hours with a detailed quotation including material, fabrication, coating, packing, and shipping costs. Our engineering team prepares shop drawings for your review before production begins, and the full mill test certificate package travels with every shipment.
Request Your Quotation and Mill Test Certificate Today
Submit your ASTM A106 seamless carbon steel structure pipe specifications, quantities, and delivery requirements to receive a detailed quotation with full material certification documentation.
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
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
