Sihe Steel
Sihe Steel
Explore our high-performance 304 and alloy grade pipelines designed to meet stringent global industrial standards.
A comprehensive engineering breakdown of chemical parameters, tolerances, and metallurgical advantages.
At the core of modern fluid transfer systems, instrumentation setups, and structural engineering is the 304-grade austenitic stainless steel. Known globally under the ASTM A269 / A312 and EN 10216-5 specifications, 304 stainless steel is defined by its balanced chemical composition—primarily featuring 18% chromium and 8% nickel. This metallurgical profile enables the formation of a self-healing chromium oxide passive layer that protects the internal and external surfaces against corrosive environments.
As an industry-leading 304 Stainless Steel Precision Pipe Factory, we understand that precision goes far beyond standard sizing. True precision entails strict control over dimensional limits, concentricity, grain structure, and surface roughness. In applications such as semiconductor manufacturing, chromatographic systems, and medical devices, even microscopic wall variations or minor interior line roughness (Ra > 0.4 µm) can lead to fluid turbulence, particle contamination, or system wear.
| Element (Wt. %) | Carbon (C) | Manganese (Mn) | Silicon (Si) | Phosphorus (P) | Sulfur (S) | Chromium (Cr) | Nickel (Ni) | Nitrogen (N) |
|---|---|---|---|---|---|---|---|---|
| 304 Grade | ≤ 0.08 | ≤ 2.00 | ≤ 0.75 | ≤ 0.045 | ≤ 0.030 | 18.0 - 20.0 | 8.0 - 10.50 | ≤ 0.10 |
| 304L Grade | ≤ 0.03 | ≤ 2.00 | ≤ 0.75 | ≤ 0.045 | ≤ 0.030 | 18.0 - 20.0 | 8.0 - 12.00 | ≤ 0.10 |
The high chromium content ensures rapid oxidation and passive-film rebuilding. Ideal for offshore instrumentation, subsea umbilicals, and harsh chemical processors.
Leveraging multi-pass cold-drawing lines, we guarantee Outer Diameter (OD) and Wall Thickness (WT) tolerances down to ±0.05 mm for specialized configurations.
Online induction annealing in a controlled hydrogen/nitrogen atmosphere prevents scaling, maintaining a reflective finish and high mechanical ductility.
Over a decade of industry expertise, utilizing advanced tooling and high-precision inspection pipelines.
Established in the heart of China's high-grade metallurgy region, Liaocheng Sihe Stainless Steel Material LTD is a leading expert in the production of stainless steel coiled tubes, polishing tubes, and seamless coiled tubing. Armed with six production lines, we support global infrastructure, manufacturing pipelines to national and international standards, including GB, ASTM, ASME, JIS, and EN.
Our core focus is the processing of steel types including 304/304L, 316L, 321, 317L, 309S, 310S, and INCOLOY 800/825. Utilizing specialized online bright annealing systems, we deliver seamless tubes and continuous coiled lines up to 32,800 feet (10,000 meters) in length. This capability is critical for manufacturing subsea control lines and downhole chemical injection lines without mechanical joints.
To serve critical sectors like military aerospace, semiconductor manufacturing, and petrochemical engineering, we implement a strict safety testing protocol. Every production batch undergoes comprehensive mechanical testing, including:
Providing custom materials to withstand harsh operating conditions across various global supply chains.
As oil and gas extraction operations shift into deeper waters and high-pressure reservoirs, umbilical systems and downhole tubes face challenging operating environments. High concentrations of hydrogen sulfide (H2S), chlorides, and carbon dioxide (CO2) can cause pitting corrosion and stress-corrosion cracking in standard metals.
To address these conditions, we supply tailored metallurgy, including Duplex 2205, Super Duplex 2507, Incoloy 825, and Inconel 625. By manufacturing seamless coiled tubing up to 10,000 meters in continuous length, we reduce the need for orbital welds. This lowers the risk of localized corrosion or mechanical fatigue, protecting deep-water systems from operational down-time.
For onshore and standard marine systems, our 304/304L and 316/316L precision tubes provide a reliable option. They support pneumatic control lines, hydraulic actuators, and subsea sampling bundles.
We customize dimensions, lengths, and surface finishes to meet project requirements.
High-precision manufacturing processes tailored to your specific system drawings and material configurations.
We support various materials (e.g., 304, 316L, 2205) and specifications (outer diameter 6.35 mm to 19 mm) for custom-coiled heat exchangers and cooling loops.
Laser and mechanical cutting options ensure close tolerances, clean edges, and clean internal bores. This minimizes burrs and contamination for semiconductor and process instrumentation.
Bright annealing (BA) and mechanical polishing provide high surface consistency, helping prevent product build-up and corrosion in pharmaceutical systems.
We supply custom-flanged tubes ready for mechanical joints in automotive exhaust setups, chemical processes, and analytical instruments.
How our factory achieves material softening, scale-free surfaces, and high mechanical performance.
During the cold-working phase (drawing and rolling), the grain structure of 304 and other austenitic steels becomes work-hardened. This increases mechanical strength but reduces ductility. To make the steel formable again for bending and coil fabrication, recrystallization is required.
Standard annealing methods expose the pipe to ambient air, causing oxidation and a dark oxide layer that must be removed by chemical pickling. At Liaocheng Sihe Stainless Steel Material LTD, we use controlled atmosphere bright annealing (BA).
Each batch of 304 stainless steel precision pipes is shipped with complete documentation. Our mill test certificates (MTC) trace the material back to the original ladle pour, detailing:
Find answers to common questions about our technical specifications, ordering processes, and shipping terms.
Explore our complete range of specialized exchanger tubes, coiled lines, and corrosion-resistant alloys.
