Sihe Steel
Sihe Steel
Explore our premium selection of industrial tubes manufactured in compliance with international ASTM, JIS, DIN, and GB standards.
Based in China, Liaocheng sihe stainless steel material LTD is a leading expert in the fields of high-precision stainless steel coiled tubes, stainless steel polishing tubes, and seamless coiled tubing. Utilizing six highly specialized production lines, we strictly manufacture products to conform to global specifications including GB, ASTM, ASME, JIS, and EN standards.
Our comprehensive steel grade capability spans from standard Austenitic materials (304/304L, 316L, 321, 317L, 309S, 310S), specialized Super Austenitics, Duplexes (Duplex 2205, Super Duplex 2507), to nickel-based superalloys (Incoloy 800, Incoloy 825, Inconel 625).
Our plant incorporates industry-leading bright annealing technology. This allows for inline steel pipe softening, keeping the internal and external surfaces completely free of oxide scale, optimizing mechanical elasticity and corrosion resistance.
A comprehensive analysis of structural composition, high-temperature performance, global market applications, and fabrication innovations.
ASTM A269 regulates seamless and welded austenitic stainless steel tubing for general service, but when applied to modified ferritic formulations such as Grade 409 (JIS SUH409 / EN 1.4512), it guarantees strict dimensional tolerances, mechanical integrity, and high-temperature oxidation profiles. Grade 409 is a titanium-stabilized ferritic stainless steel containing approximately 11% chromium. Titanium addition acts as a stabilizer, preventing sensitization during welding and localized intergranular corrosion.
Historically, Austenitic grades (such as 304 and 316) dominated coiled tube specifications. However, the extreme fluctuations in nickel and molybdenum commodity pricing have driven engineers to explore alternative alloys. Grade 409 offers a highly competitive thermal expansion coefficient lower than austenitic grades, translating to reduced thermal fatigue and mechanical strain in high-temperature applications.
At Liaocheng Sihe, the manufacturing journey of ASTM A269 409 coiled tubing involves state-of-the-art cold-drawing (precision plug and sink drawing) and continuous online welding systems. Our 10,000-meter (32,800 ft) continuous tube production bypasses the necessity for frequent orbital joint welding, significantly eliminating failure points across high-pressure hydraulic lines and offshore umbilical applications.
Crucial to this process is the protective atmosphere Bright Annealing (BA) treatment. Undertaken in a controlled hydrogen-nitrogen gas environment above 1040°C, the steel recrystallizes without reacting with oxygen. The resulting tube possesses a brilliant reflective finish, clean internal diameters, and optimized ductility necessary for secondary processes like flanging, expanding, and bending.
To guarantee extreme safety for systems operating in offshore deepwater, chemical reactors, or automotive chassis, we execute a rigorous series of destructive and non-destructive testing (NDT):
Currently, 80% of our manufactured coiled tubing exports reach the United States and North American distribution networks, with the remainder supplying Germany, Spain, South America, Southeast Asia, and Eastern Europe.
This heavy demand in Western markets is driven by the tightening emissions laws in the automotive sector (which utilize SUH409 for exhaust system tubing) and the rapid expansion of solar thermal exchangers, geothermal heat extraction loops, and deep-sea oil exploration umbilicals requiring durable, corrosion-resistant, and cost-effective metal lines.
| Element / Property | ASTM A269 409 (UNS S40900) | ASTM A269 304 (UNS S30400) | ASTM A269 316L (UNS S31603) | Duplex 2205 (UNS S32205) |
|---|---|---|---|---|
| Chromium (Cr) % | 10.5 - 11.75% | 18.0 - 20.0% | 16.0 - 18.0% | 22.0 - 23.0% |
| Nickel (Ni) % | Max 0.5% | 8.0 - 11.0% | 10.0 - 14.0% | 4.5 - 6.5% |
| Molybdenum (Mo) % | - | - | 2.0 - 3.0% | 3.0 - 3.5% |
| Stabilizer | Ti: 6x(C+N) to 0.75% | None | None | None |
| Tensile Strength (MPa) | ≥ 380 | ≥ 515 | ≥ 485 | ≥ 655 |
| Yield Strength 0.2% (MPa) | ≥ 170 | ≥ 205 | ≥ 170 | ≥ 450 |
| Thermal Exp. (x10^-6/K) | 11.0 (at 100-500°C) | 17.2 (at 100-500°C) | 16.0 (at 100-500°C) | 13.7 (at 100-500°C) |
High-tech secondary post-processing capabilities to deliver ready-to-install components directly to your production floor.
We support multiple raw materials including 304, 316L, and Duplex 2205. Our processes accommodate outer diameters ranging from 0.125 inches (3.175 mm) up to 1 inch (25.4 mm), with custom dimensional configurations.
Our manufacturing line provides precision engineering solutions, including complex multi-radius bending, compact spiral configurations, high-pressure coil drawing, and heat exchanger assembly integrations.
Choose from high-precision laser cutting, orbital mechanical sawing, or flame cutting options. We deliver tight tolerance cuts and straightened sections suited for rapid automatic assembly lines.
We customize surface finishes using mechanical polishing, electro-polishing, pickling, or sandblasting to target precise roughness parameters (Ra value) required by sanitary biotechnology and cleanrooms.
Engineered for leak-free integrations in automotive exhaust manifolds, chemical transport systems, and marine hydraulics. We offer secure flared ends and custom flange connections.
A structured view of our manufacturing range, highlighting specialized applications and dimensions.
High-end 2205 Duplex and 316L grades containing austenitic and ferritic microstructures for extreme subsea corrosion resistance.
Standard 1/2 inch outer diameter coils designed for fluid transport pipelines, control lines, and industrial instrument panels.
High-temperature oxidation-resistant 310/310S grade coils suited for combustion chambers and furnace gas transport lines.
Engineered for petrochemical thermal systems, condensers, and cooling towers under aggressive chemistry regimes.
Ultra-fine dimensional tubes down to 0.125-inch OD, ideal for gas chromatography (GC) and liquid handling instruments.
Single continuous coils up to 32,800 feet, avoiding mid-span joints for subsea downhole control systems.
Processed in zero-oxygen atmospheres to achieve high surface reflectivity and scale-free interior passages.
Provides uniform, smooth interior pathways that reduce turbulent fluid friction in high-velocity systems.
Designed for chemical processing vessels, geothermal installations, and extreme deep-sea acid environments.
Engineered with wall thicknesses up to 3mm (0.165 inches) to withstand high pressure gradients.
High-quality structural sheets and plates matching coiled tubing chemistries for integrated structural fabrications.
Flexible manufacturing setups designed to create custom outer diameters, wall thicknesses, and alloy designs.
Engineered for high heat-transfer coefficients and mechanical stability under high pressure and thermal cycling.
Our tubing products are integrated into high-stakes industrial systems across multiple global sectors.
Our mill is certified to conform to international standards, providing complete traceability and document verification.
Professional procurement and engineering answers for stainless steel coiled tubing solutions.
Additional specifications and grades manufactured inside our Liaocheng facility.
