Sihe Steel
Sihe Steel
Select precision-engineered structural and capillary metal parts manufactured to international tolerance standards.
In the world of high-stress thermal systems, 310 Stainless Steel Capillary Tubes represent the pinnacle of micro-bore piping resilience. Engineered from a robust austenitic alloy with an elevated concentration of chromium (24% to 26%) and nickel (19% to 22%), Grade 310 (UNS S31000) and its low-carbon variant 310S (UNS S31008) are custom-synthesized to thrive under extreme atmospheric conditions. Unlike standard structural piping, capillary lines require absolute structural integrity to maintain precise fluid flow metrics under pressure ranges exceeding several hundred bars.
Liaocheng Sihe Stainless Steel Material LTD has engineered a comprehensive metallurgical process that preserves the micro-grain structural integrity of 310S during the cold-drawing process. The high chromium-nickel composition establishes a stable oxide barrier phase that inhibits oxidation, preventing carbide precipitation and surface degradation at operational thermal thresholds up to 1150°C (2102°F) in continuous service. This makes 310S capillary tubing the premium selection for microfluidics in petrochemical crackers, furnace probe chambers, and high-purity laboratory control valves.
| Alloy Grade | Chromium (Cr) % | Nickel (Ni) % | Carbon (C) % Max | Max Service Temp (°C) | Primary Industrial Applications |
|---|---|---|---|---|---|
| 310 / UNS S31000 | 24.00 - 26.00 | 19.00 - 22.00 | 0.25 | 1150 | Kiln parts, furnace instrumentation, gasifiers |
| 310S / UNS S31008 | 24.00 - 26.00 | 19.00 - 22.00 | 0.08 | 1150 | Petrochemical, chemical microfluidics, thermal wells |
| Incoloy 825 | 19.50 - 23.50 | 38.00 - 46.00 | 0.05 | 540 | Deep-water umbilical lines, highly corrosive acids |
| Super Duplex 2507 | 24.00 - 26.00 | 6.00 - 8.00 | 0.030 | 300 | Offshore oil extraction, marine chloride environments |
High-precision systems require supply chains that understand the localized engineering tolerances demanded by international standards. Whether implementing high-pressure instrumentation networks in North American aerospace assembly facilities, setting up micro-scale heat exchangers in European chemical plants, or running specialized offshore umbilical control lines in the harsh North Sea, specifying the right capillary material dictates system longevity.
Global procurement teams prioritize three primary parameters when evaluating Chinese stainless steel factories:
Our factories sustain tolerances as tight as ±0.01mm on micro-bore tubing. This level of control is crucial to ensure fluid dynamics align with computational models, preventing pressure drops or localized cavitation.
In medical fluidics and analytical chromatography systems, high wall roughness causes drag and product contamination. We target internal surface roughness (Ra) down to ≤0.4μm via optimized cold-drawing lubricants and modern drawing dies.
For continuous pressure-retaining applications, physical properties must be uniform. Online bright annealing ensures consistent yield strength and ductility across kilometers-long coils.
Our manufacturing footprint combines precision metallurgy with certified global distribution capabilities.
The precision metal tubing industry has progressed past traditional multi-stage drawing workshops. Modern metallurgical facilities operate under unified quality control structures, linking real-time dimensional verification with automated furnace management. At Liaocheng Sihe, we use advanced technology to stabilize chemical properties, control wall integrity, and maintain high surface purity.
A core asset in our production flow is the online Bright Annealing System. Operating under high-purity hydrogen atmosphere shielding, this system heats the cold-worked stainless steel tube to temperatures exceeding 1040°C before rapidly cooling it in a clean environment. This process prevents oxygen interaction, averts surface oxidation, and ensures the tubing remains shiny and structurally sound, removing the need for acid pickling.
| Test Type | Methodology / Standard Compliance | Quality Objective |
|---|---|---|
| Air Tightness & Pneumatic Test | 100% online pressurized air immersion (up to 150 Bar) | Identifies micro-pinholes, seams, and macro-defects in coiled tubing. |
| Hydrostatic Testing | ASTM A450 standard water pressure retention tests | Confirms structural integrity of walls under specified load limits. |
| Mechanical Flaring & Bending | Ductility testing via standard taper expansion tests | Validates plasticity to ensure no cracking during field bending. |
| Hardness Verification | 100% Rockwell / Vickers micro-hardness profiling | Confirms correct crystallization state following bright annealing. |
Because of their balance of high thermal resistance, oxidation defense, and structural elasticity, 310 and 310S capillary tubing are used across critical industrial applications.
Standard tubes often require additional processing to fit directly into specialized machinery. Our facilities offer downstream metal fabrication services, allowing you to source ready-to-install parts that reduce your assembly cycle times.
We support customized geometries, tight-radius spiral bends, and dual-layer heat exchanger coils. This is done with precision tooling to prevent ovality or flattening in the cross-section.
We provide laser-cut tube lengths with square, burr-free ends, as well as straightened tube sections. These are prepared to tolerances suitable for automatic robotic welding processes.
For automotive and process systems, we offer expanded or flanged ends. This allows for direct fitting integration without using separate adapters.
For pharmaceutical biotechnology and semiconductor installations, we offer chemical electropolishing. This process creates a clean interior surface, reducing fluid friction and particle retention.
Quality assurance is verified by third-party testing and international manufacturing audits. We maintain compliance with standards such as ASTM A269, ASTM A213, EN 10216-5, and JIS G3459.
Technical answers directly from our factory engineering team regarding specifications, lead times, and customization options.
Explore our custom-processed steel plates and specialty coiled tubing designed for high-stress applications.
