Sihe Steel
Sihe Steel
Direct factory wholesale selections conforming to ASTM, ASME, JIS, EN, and GOST international standards.
Understanding critical tolerances, dimensional metrics, and performance limits for extreme industrial services.
Industrial capillary tubes are characterized by highly restricted dimensional profiles. Standard outer diameters (OD) range from 0.125 inch (3.175 mm) to 1 inch (25.4 mm), with wall thicknesses reaching up to 0.165 inch (3 mm). Special micro-precision dimensions down to 0.02 inches (0.5 mm) can be drawn. Accurate ID/OD ratios are crucial to avoid pressure drops and flow turbulences in HPLC and chromatography systems.
As deepwater exploration, aerospace engineering, and semiconductor fabrication scale globally, procurement teams require materials capable of surviving high chloride, high heat, and ultra-high pressure environments. Bulk buyers prioritize continuous coil length availability (up to 10,000 meters / 32,800 feet) to minimize mechanical fittings and weld joints, directly mitigating the risk of structural leaks in subsea control lines.
Securing factory quotes requires alignment on lead times and certifications. Custom samples typically require a 7-day delivery cycle, while mass manufacturing operations operate on a 20-to-30-day schedule upon deposit verification. Standard packing involves export wooden crates or heavy-duty plastic spools for coiled formats, ensuring zero ovality deformation during transoceanic shipping.
Technical Note: Maintaining concentricity tolerances below ±0.02mm is essential for high-performance applications. The selection of drawing passes (plug drawn vs. sink drawn) directly affects inner surface roughness (Ra < 0.4μm for chromatography applications).
Reference table illustrating outer diameters, wall thicknesses, and weight parameters under global compliance guidelines.
| Outer Diameter (OD) - Inches | Outer Diameter (OD) - Metric (mm) | Wall Thickness (WT) - Inches | Wall Thickness (WT) - Metric (mm) | Theoretical Weight (g/m) | Applicable Alloy Grades |
|---|---|---|---|---|---|
| 0.0625" | 1.59 mm | 0.010" - 0.020" | 0.25 mm - 0.51 mm | 8.3 - 13.8 | 316L, 304, Inconel 625 |
| 0.125" | 3.18 mm | 0.020" - 0.035" | 0.51 mm - 0.89 mm | 34.1 - 51.2 | 304L, 316L, Duplex 2205 |
| 0.250" | 6.35 mm | 0.035" - 0.049" | 0.89 mm - 1.24 mm | 122.1 - 159.2 | 316L, Duplex 2205, Incoloy 825 |
| 0.375" | 9.53 mm | 0.035" - 0.065" | 0.89 mm - 1.65 mm | 193.5 - 326.1 | 316L, 321, 310S, Super Duplex 2507 |
| 0.500" | 12.70 mm | 0.049" - 0.083" | 1.24 mm - 2.11 mm | 356.4 - 560.8 | 304/L, 316/L, Alloy 825, Alloy 625 |
| 0.750" | 19.05 mm | 0.065" - 0.109" | 1.65 mm - 2.77 mm | 719.4 - 1131.2 | 316L, Duplex 2205, Incoloy 825 |
| 1.000" | 25.40 mm | 0.083" - 0.120" | 2.11 mm - 3.05 mm | 1232.0 - 1711.5 | 304L, 316L, 310S, 321, 2205 |
A strategic overview of material evolution and processing upgrades supporting critical infrastructure sectors.
Modern petrochemical and subsea systems demand materials that withstand high concentrations of chloride and hydrogen sulfide. Utilizing high-performance grades such as Duplex 2205, Super Duplex 2507, Incoloy 825, and Inconel 625 allows engineering teams to optimize wall thickness while preventing pitting corrosion (PREN > 40 for Super Duplex) and stress corrosion cracking (SCC).
Processing capillary and coiled tubing requires inline bright annealing furnaces with high-purity hydrogen gas. This heat treatment operates above 1050°C and is followed by rapid cooling, ensuring the complete dissolution of chromium carbides into the austenitic matrix. This method eliminates surface oxidation, yields a bright inner/outer finish, and optimizes ductility for downstream bending, flaring, and coiling procedures.
Looking ahead, the demand for capillary tubing is scaling alongside developments in hydrogen fuel cell systems, aerospace liquid fuel lines, and precision chromatography. Innovations in micro-cold drawing are targeting OD tolerances of ±0.005 mm. Additionally, smart metallurgy integration is helping to prevent carbon precipitation in ultra-low carbon grades (e.g., 316L, 304L) during high-temperature thermal cycling.
Liaocheng Sihe Stainless Steel Material LTD: A premier manufacturer of precision stainless steel coiled and capillary tubing.
Liaocheng sihe stainless steel material LTD (From China) operates six advanced production lines and specializes in high-quality Sheet and Pipe Development. We are a leading expert in the production of stainless steel coiled tubes, polishing tubes, and seamless coiled tubing, adhering to international manufacturing standards including GB, ASTM, ASME, JIS, and EN.
Our alloy expertise encompasses critical grades: 304/304L, 316L, 321, 317L, 309S, 310S, INCOLOY 800, Austenitic Steel 316L, Duplex 2205, Super Duplex 2507, Incoloy 825, and Inconel 625.
With over a decade of production history and three dedicated coil lines, our manufacturing facility has introduced world-class bright annealing technology for online softening treatments. Quality assurance is maintained through a complete testing suite: hydrostatic compression, flaring, bending, 100% hardness tests, tensile testing, and air-tightness verification. Currently, up to 80% of our products are exported globally, serving customers in the United States, Germany, Spain, South America, Southeast Asia, the Middle East, and Eastern Europe.
Our coiled and capillary tubes are designed to withstand high pressure, corrosive chemicals, and extreme temperatures. These properties make them highly valued in sectors such as military technology, semiconductor fabrication, pharmaceutical biotechnology, hydraulic systems, boilers, aerospace engineering, automotive manufacturing, and subsea exploration.
Available Sizes: Outer diameters range from 0.125 inch (3.175 mm) to 1 inch (25.4 mm). Wall thicknesses are available up to 0.165 inch (3 mm), and continuous lengths can reach up to 32,800 feet (10,000 meters) without orbital butt welds. Custom dimensions outside this standard range can also be manufactured to meet specific application requirements.
Ensuring material traceability and structural reliability under harsh operating conditions.
A broad selection of stainless steel and high-nickel alloy solutions engineered for industrial applications.
High-integrity Duplex 2205 seamless coils designed to withstand corrosive and high-pressure environments.
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Precision-drawn coiled tubing available in 1/2-inch and other common sizes for fluid transport systems.
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Heat-resistant 310 grade stainless steel coiled tubing, optimized for elevated temperature applications.
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Seamless coiled tubing in standard and custom alloys, optimized for oil and gas installations.
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Precision micro-bore tubes designed for high-pressure chromatography, medical devices, and analytical instruments.
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High-efficiency heat exchanger pipes engineered for optimized thermal transfer and corrosion resistance.
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Industrial-grade structural sheets and plates available in multiple surface finishes and thicknesses.
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High-ductility sheets available in grades 304, 316L, and 430, suitable for custom fabrication projects.
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Heat-treated tubes with a clean, smooth inner surface to support high-purity fluid delivery systems.
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High-pressure hydraulic tubes, manufactured to exact dimensional tolerances to ensure leak-free performance.
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Reliable instrumentation tubing designed to maintain precise pressure transmission in control loops.
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Specialty Inconel 625 and Incoloy 825 tubes built to perform in highly acidic and high-temperature environments.
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Ultra-clean inner diameter tubes designed specifically for gaseous delivery in semiconductor facilities.
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Thin-walled, micro-bore capillary coils supplied in continuous lengths for chromatography applications.
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Super Duplex and Incoloy alloy tubing engineered for offshore umbilical control lines.
LEARN MOREOur custom processing services support downstream integration across a variety of industrial applications.
Supporting multiple grades (including 304, 316L, and 2205) with outer diameters from 6.35 mm to 19 mm, tailored to specific engineering drawings.
Providing precision bending, coil forming, and spiral fabrication designed for heat exchange and condensation systems.
Utilizing high-precision laser and mechanical cutting to deliver square, burr-free tube ends ready for orbital welding.
Offering polishing, pickling, passivation, and electropolishing (EP) to reduce inner surface roughness and prevent particulate accumulation.
Providing custom end prep, flanging, expansion, and reduction to support integration into automotive, subsea, and industrial systems.
Our capillary and coiled tubing products are utilized across multiple demanding industrial environments.
Technical guidance and commercial parameters for procurement managers and mechanical engineers.
Our standard manufacturing processes support OD and ID tolerances of ±0.05 mm. For ultra-precision applications such as liquid chromatography and aerospace fuel delivery, we can control tolerances down to ±0.02 mm through multi-pass cold drawing and precise plug control.
Material selection depends heavily on your operating environment. Grade 316L is suitable for general chemical processing and biotechnology. Duplex 2205 provides higher yield strength and localized pitting resistance, while Incoloy 825 and Inconel 625 offer excellent performance in high-chloride, sour gas (H2S), and elevated-temperature subsea applications.
Every shipment is accompanied by Mill Test Certificates (MTC) in accordance with EN 10204 3.1. We provide detailed chemical analysis, mechanical property verification, eddy current testing, hydrostatic pressure reports, air-tightness testing, and hardness measurements.
Standard lead times are approximately 7 days for customized samples and 20 to 30 days for mass production orders. As an export-oriented manufacturer, we work with domestic and international buyers to establish appropriate production volumes based on the specific alloy grade, wall thickness, and spool length requested.
To prevent bending, ovality, or surface abrasion during transit, coiled tubing is wound onto wooden or steel drums, wrapped in protective plastic, and secured within reinforced wooden crates. Specialized packaging can also be arranged for heat-sensitive or high-purity shipments.
Online bright annealing processes the tubing in a controlled hydrogen atmosphere at high temperatures. This prevents surface oxidation and scaling, resulting in a clean, smooth inner and outer finish. It also restores ductility, making the tubing easier to bend, flare, and coil during field installation.
Explore our complete product catalog for heat exchangers, automotive exhaust, and high-pressure hydraulic lines.
