Sihe Steel
Sihe Steel
High-precision stainless steel, duplex, and nickel alloy tubing designed to meet strict international standards.
As a leading pioneer in China's metallurgical landscape, Liaocheng Sihe Stainless Steel Material LTD specializes in producing high-performance, corrosion-resistant seamless stainless steel coiled tubing, precision capillary tubes, and heat exchanger pipes. Armed with 6 advanced production lines and over a decade of processing experience, we strictly enforce domestic and international standards (including GB, ASTM, ASME, JIS, and EN).
Our bright annealing line provides a clean, oxygen-free processing window, allowing online structural softening that guarantees excellent ductility and flawless mechanical characteristics. This makes our tubes the materials of choice for demanding industries such as subsea exploration, pharmaceutical biotechnology, and aerospace hydraulics.
A comprehensive analysis of metallurgical structures, manufacturing tolerances, and quality verification.
Industrial fluid systems operating under high temperatures, cyclic pressure loading, and corrosive environments demand strictly controlled chemical compositions. Liaocheng Sihe manufactures seamless tubing utilizing premium austenitic steels, duplex/super duplex alloys, and high-nickel formulations:
| Alloy Grade | UNS Number | Chromium (Cr) % | Nickel (Ni) % | Molybdenum (Mo) % | Yield Strength (Mpa, Min) |
|---|---|---|---|---|---|
| 316L | S31603 | 16.0 - 18.0 | 10.0 - 14.0 | 2.0 - 3.0 | 170 |
| Duplex 2205 | S31803 / S32205 | 22.0 - 23.0 | 4.5 - 6.5 | 3.0 - 3.5 | 450 |
| Super Duplex 2507 | S32750 | 24.0 - 26.0 | 6.0 - 8.0 | 3.0 - 5.0 | 550 |
| Incoloy 825 | N08825 | 19.5 - 23.5 | 38.0 - 46.0 | 2.5 - 3.5 | 240 |
| Inconel 625 | N06625 | 20.0 - 23.0 | 58.0 Min | 8.0 - 10.0 | 410 |
Our manufacturing lines support outer diameters (OD) spanning from 0.125 inches (3.175 mm) to 1.0 inch (25.4 mm), with wall thicknesses reaching 0.165 inches (3 mm). By using high-ratio cold-drawing blocks and specialized lubricants, we consistently maintain wall thickness tolerances below ±7.5%, and outer diameter tolerances below ±0.05 mm.
Continuous Coiled Lengths: For marine umbilical networks and control lines, joints represent points of structural weakness and potential chemical leaks. Liaocheng Sihe is capable of outputting single, continuous seamless coiled lines up to 32,800 feet (10,000 meters). This eliminating orbital welding requirements during downhole and deep-sea installation, maximizing line integrity and reducing costs.
Reliability in high-pressure oil exploration and subsea deployments demands comprehensive defect detection. Liaocheng Sihe operates an in-house laboratory equipped to perform multiple critical mechanical and non-destructive evaluations:
Tailored mechanical designs engineered for the most demanding operating parameters.
Value-added manufacturing to meet exact blueprint dimensions and system specifications.
Supports processing across all common materials (304, 316L, 2205) and custom specifications, covering tube diameters ranging from 6.35 mm to 19 mm.
Comprehensive capabilities including tight-radius bending, customized spiral configurations, and micro-precision drawing tailored for heat transfer packages.
Multi-axis laser cutting, mechanical saws, and precise flame systems to achieve exact straight lengths with minimal burr formations.
State-of-the-art chemical passivation, mechanical polishing, and bright hydrogen annealing to deliver internal Ra values as low as 0.4 microns.
Optimized flanging profiles engineered for secure mechanical integration inside complex automotive exhaust networks and high-pressure chemical joints.
Online bright annealing softens steel structures and prevents surface oxidation, ensuring optimal flexibility for downstream installations.
Demonstrated compliance with global standards, guaranteeing safety, performance, and traceabilities.
Decarbonization, deepwater exploration, and sourcing strategies for international procurement teams.
The global market for seamless stainless steel tubing is experiencing a significant shift due to volatile nickel prices, shipping constraints, and the rising demand for green energy infrastructures. Chinese factories, particularly those with vertical integration models like Liaocheng Sihe, provide strong supply chain resilience:
With the global shift towards green hydrogen energy systems, transport tubing must resist hydrogen embrittlement. Austenitic stainless steel grades with high nickel equivalents (such as specialized 316/316L and XM-19) are critical. The high-purity interior surfaces produced by our bright hydrogen annealing technology prevent localized stress risers, ensuring safe high-pressure hydrogen gas containment up to 700 bar.
Explore our core product ranges by manufacturing type and form factor.
Duplex and austenitic seamless coils designed for high pressure hydraulic and chemical injection control lines.
View Category
Micro-bore tubes tailored for precision instrumentation, chromatography systems, and medical devices.
View Category
Straight and U-bent seamless tubes optimized for power plants, boilers, and industrial condensation processes.
View Category
High-grade structural sheets and plates supporting heavy chemical reactors, storage vessels, and fabrication.
View CategoryA visual tour of our rolling, drawing, spooling, and finishing facilities in China.
Detailed technical and commercial inquiries answered by our engineering and logistics teams.
Our pricing is calculated based on current LME (London Metal Exchange) base metal values (such as nickel, molybdenum, and chromium), along with order volumes and specific fabrication needs. For current rates on stainless steel, duplex, or nickel alloys, please submit your detailed specifications to our sales desk. We will provide an updated, itemized quotation within 24 hours.
For standard sizes, we require a minimum order volume of 500 kg to 1,000 kg depending on the alloy class (e.g., higher MOQs apply to custom runs of duplex or nickel alloys). If you are looking to source smaller trial quantities, please contact us to check available warehouse stock.
Yes, we provide comprehensive documentation for every shipment. This includes EN 10204 3.1 Mill Test Reports (MTRs), PMI chemical analysis certifications, hydrostatic pressure charts, eddy current inspection logs, and certificate of origin documents.
Standard prototype and sample runs take approximately 7 days. Large-scale production and custom orders average 20 to 30 days after drawing approval and deposit receipt. We work closely with logistics partners to ensure delivery windows align with your project schedule.
We accept bank telegraphic transfers (T/T), L/C (Letters of Credit) at sight, Western Union, and PayPal. Our typical commercial terms are a 30% deposit to initiate production, with the remaining 70% balance paid upon presentation of the Bill of Lading (B/L) copy.
We guarantee the chemical composition and mechanical properties of our products to match ASTM, EN, and ASME specifications. Any material defects or out-of-tolerance issues will be resolved in accordance with our quality assurance agreement, which includes replacement or credit options.
We use heavy-duty export packaging, including custom wooden spools, steel-reinforced reels, and protective wrapping. This secures the coiled tubes against sea mist, moisture, and mechanical impact during multi-mode transport.
Shipments are managed based on your requested Incoterms (FOB, CFR, CIF, DDU/DDP). Small express shipments are sent via air transport, while high-volume bulk or containerized orders are routed through the ports of Qingdao, Shanghai, or Tianjin to optimize shipping costs.
Select from our certified range of capillary, polished, and custom-grade tubing.
