Sihe Steel
Sihe Steel
Direct supply from manufacturing lines. Compliance with international standards: GB, ASTM, ASME, JIS, and EN.
An in-depth guide on performance metrics, thermodynamic limits, and selection criteria for 304, 316L, and advanced super-alloys.
When selecting stainless steel tubing for critical industrial applications, understanding the microstructural differences between Grade 304 (UNS S30400) and Grade 316L (UNS S31603) is vital. Grade 304 contains 18% chromium and 8% nickel, providing standard resistance to atmospheric oxidation. However, in environments with chlorides, acids, or high moisture, Grade 304 is prone to localized pitting and crevice corrosion.
Grade 316L solves this vulnerability through the addition of 2% to 3% molybdenum. Molybdenum increases the Pitting Resistance Equivalent Number (PREN), protecting the passive chromium oxide layer against chloride ions. The "L" in 316L denotes a low carbon content (maximum 0.03%), which prevents grain boundary carbide precipitation during welding. This protects the heat-affected zone (HAZ) from intergranular corrosion.
"For subsea operations, chemical processing plants, and marine infrastructure, choosing Grade 316L over Grade 304 is crucial. This decision affects the system's operational lifetime, safety factors, and total lifecycle costs."
At Liaocheng Sihe Stainless Steel Material LTD, we maintain high standards across all six of our advanced production lines. We supply high-quality coiled tubing, heat exchanger pipes, and polished capillaries to meet strict international standards, ensuring your project operates without issues.
| Steel Grade | Chromium (Cr) % | Nickel (Ni) % | Molybdenum (Mo) % | Carbon (C) % Max | Tensile Strength (MPa) Min | Yield Strength (MPa) Min |
|---|---|---|---|---|---|---|
| 304 / 304L | 18.00 - 20.00 | 8.00 - 10.50 | - | 0.08 / 0.03 | 515 | 205 |
| 316 / 316L | 16.00 - 18.00 | 10.00 - 14.00 | 2.00 - 3.00 | 0.08 / 0.03 | 485 | 170 |
| Duplex 2205 | 21.00 - 23.00 | 4.50 - 6.50 | 2.50 - 3.50 | 0.03 | 655 | 450 |
| Super Duplex 2507 | 24.00 - 26.00 | 6.00 - 8.00 | 3.00 - 5.00 | 0.03 | 800 | 550 |
Over a decade of manufacturing excellence in stainless steel coiled tubing, polishing tubes, and seamless industrial solutions.
Established as a specialized manufacturer, Liaocheng Sihe Stainless Steel Material LTD operates six production lines dedicated to producing high-quality stainless steel tubes, coils, and sheets. Our expertise covers stainless steel coiled tubing, polishing tubes, and seamless coiled tubing.
We strictly follow global standards including GB, ASTM, ASME, JIS, and EN. We process austenitic grades (304/304L, 316L, 321, 317L, 309S, 310S) and high-performance alloys (Duplex 2205, Super Duplex 2507, Incoloy 825, Inconel 625).
Our facility features the world's leading bright annealing technology, allowing inline softening of pipes to optimize flexibility and ductility. To ensure reliability, we conduct compression, flaring, bending, 100% hardness, tensile, and air tightness testing.
Years of Manufacturing
Advanced Production Lines
Exporting Countries
Continuous Tubing Lengths
Our commitment to precision is supported by international quality certifications. We guarantee the quality of every batch we ship.
Our stainless steel tubes are engineered to withstand extreme conditions, from deep-sea offshore operations to cleanroom environments.
High thermal conductivity, corrosion-resistant tube bundles for power plants and refineries.
Coiled configuration ensures seamless routing, preventing fluid leaks under pressure.
Resists acids, bases, and volatile compounds, maintaining material integrity.
Polished tubes prevent bacterial buildup, facilitating CIP (Clean-in-Place) cleaning.
Ultra-high purity capillary tubes suitable for medical-grade transport systems.
Withstands continuous high temperature and high steam pressure cycles.
Ideal for offshore umbilical structures and downhole instrumentation.
Exhaust gas recirculation, hydraulic lines, and fuel injection systems.
Our processing center offers customization to meet the precise dimensions required by your application.
We work with various materials (304, 316L, Duplex 2205) and custom specifications, offering diameter ranges from 6.35mm to 19mm for stainless steel coils.
We offer bending, spiral forming, and precision drawing, all designed for demanding thermal projects like heat exchangers and industrial boilers.
Our services include laser cutting, high-precision mechanical cutting, and flame cutting to ensure close tolerances and clean edges.
Our options include electro-polishing, bright annealing, mechanical polishing, and passivation to meet surface roughness requirements for clean industries.
We specialize in precision flanging for automotive exhaust systems, chemical pipelines, and instrument connections.
We produce single, continuous coiled tubing lengths up to 32,800 feet (10,000 meters) without orbital welds, ideal for subsea control lines.
Addressing structural challenges through metallurgical innovation and smart supply chains.
Transitioning from basic 316L to Duplex 2205 and Super Duplex 2507 for deep-sea oil and gas extraction, enhancing safety in harsh marine environments.
Refining internal surfaces for high-tech industries, including hydrogen fuel cells, semiconductors, and pharmaceutical facilities.
Integrating online Eddy Current Testing (ECT) and ultrasonic inspections during production to ensure defect-free coiled pipes.
Ensuring compliance with localized certifications (AD2000, PED, ASME Sec VIII) for smooth customs clearance and engineering approval.
Technical guidance and commercial policies for procurement managers and design engineers.
View our selection of specialized tubes, coils, and sheets, designed to meet strict industrial specifications.
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Polished tube configurations with strict OD tolerance levels for control lines.
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High precision lines for chromatography systems and medical devices.
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Designed to withstand deep sea pressures and high salinity fluids.
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Clean-surface, high thermodynamic transfer tubes for thermal utilities.
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Molybdenum-enriched formulations for stable resistance to pitting corrosion.
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Enhanced mechanical strength profiles for pressure-safety applications.
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Withstands extreme low temperatures without experiencing brittle fracture.
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Thick-walled specifications built for high thermal stress levels.
View DetailsSelect your alloy and configuration to request a custom quote from our logistics team.
