Stainless Steel Capillary Coil Tube (Φ0.5mm – Φ3mm OD)
Product Overview
Wenzhou Jixing Metal Materials Co., Ltd. offers a premium range of precision-engineered stainless steel capillary coil tubes, available in outer diameters from Φ0.5mm to Φ3mm. These ultra-fine bore tubing products are manufactured to exacting tolerances and delivered in continuous coil form, ensuring minimal waste and maximum handling efficiency for downstream processing. Designed for the most demanding micro-scale applications, these capillary tubes combine exceptional dimensional accuracy, superior surface finish, and outstanding mechanical integrity in a single, highly versatile product.
Material & Properties
The capillary coil tubes are fabricated from high-purity austenitic stainless steel grades, predominantly 304 (S30400) and 316L (S31603), selected for their superior corrosion resistance, biocompatibility, and mechanical performance at micro-dimensions. Key material properties include:
- Corrosion Resistance: Excellent resistance to oxidation, pitting, and crevice corrosion in aggressive chemical environments and physiological fluids.
- Mechanical Strength: High tensile strength and yield strength even at sub-millimeter wall thicknesses, ensuring structural integrity under pressure and thermal cycling.
- Biocompatibility: Fully compliant with ISO 10993 standards for long-term implant and contact applications in medical devices.
- Surface Quality: Available in cold-drawn, polished, and electropolished finishes with surface roughness as low as Ra ≤ 0.1 μm for electropolished variants.
- Weldability: Excellent weldability for laser welding, TIG welding, and ultrasonic joining at micro-scale.
Specifications
| Parameter | Specification |
|---|---|
| Outer Diameter (OD) | Φ0.5 mm – Φ3.0 mm |
| Wall Thickness | 0.05 mm – 0.5 mm (customizable) |
| OD Tolerance | ±0.01 mm (standard); ±0.005 mm (precision grade) |
| Wall Thickness Tolerance | ±0.01 mm |
| Surface Roughness | Ra ≤ 0.4 μm (cold-drawn); Ra ≤ 0.1 μm (electropolished) |
| Roundness | ≤ 0.01 mm |
| Coil Form | Continuous coil; customizable coil diameter and length |
| Material Grades | 304, 304L, 316L, 321, 310S, Hastelloy C-276, Inconel 625 (on request) |
| Finish Options | Cold-drawn, mechanically polished, electropolished, passivated |
| Standard Length per Coil | 5 m – 500 m (custom lengths available) |
Manufacturing Process
Each capillary coil tube undergoes a rigorous multi-stage manufacturing process to achieve the exceptional dimensional accuracy and surface quality required for micro-scale applications:
- Raw Material Selection: Only certified, low-carbon austenitic stainless steel wire rod from approved mills is used as feedstock, ensuring traceability and consistent metallurgical quality.
- Wire Drawing: The wire rod is cold-drawn through a series of precision tungsten carbide or diamond dies to progressively reduce the diameter to the target capillary size while maintaining tight dimensional tolerances.
- Intermediate Annealing: Controlled solution annealing at precise temperatures relieves internal stresses accumulated during drawing, restoring ductility and preventing micro-cracking.
- Precision Finishing: Final drawing passes through calibrated dies to achieve the exact OD and wall thickness specifications. Electropolishing or mechanical polishing is applied as required to achieve ultra-smooth surface finishes.
- Passivation Treatment: A final chemical passivation step removes surface contaminants and enhances the passive chromium oxide layer for maximum corrosion resistance.
- Coiling & Packaging: Tubes are coiled on precision winder equipment to ensure uniform coil geometry, then individually packaged in moisture-barrier packaging with protective end caps.
Applications
The Φ0.5mm – Φ3mm capillary coil tube range is purpose-built for high-precision, micro-scale applications across multiple industries:
- Chromatography Columns: Ideal for gas chromatography (GC), high-performance liquid chromatography (HPLC), and capillary electrochromatography (CEC) columns where ultra-smooth inner surfaces and precise bore dimensions are critical for chromatographic resolution and peak efficiency.
- Microfluidic Systems: Essential for lab-on-a-chip (LOC) devices, micro-organizers, and micro-total analysis systems (μTAS) where controlled fluid transport at nanoliter to microliter flow rates is required.
- Precision Instruments: Used in mass spectrometry inlet lines, pressure sensor capillaries, thermocouple protective sheaths, and analytical instrument flow paths demanding leak-tight, corrosion-resistant micro-tubing.
- Medical Catheters & Devices: Employed in minimally invasive medical catheters, drug delivery systems, dialysis tubing, surgical guides, and implantable medical devices requiring biocompatibility, radiopacity, and mechanical reliability at micro-dimensions.
- Optical Fiber Preforms: Serves as precision capillary sleeves and jackets in the manufacture of specialty optical fibers and photonic devices.
- Fuel Cells & Energy Systems: Used in hydrogen fuel cell flow fields and micro-channel heat exchangers where tight tolerance and corrosion resistance are paramount.
Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management system to ensure every coil tube lot meets or exceeds international standards:
- ISO 9001:2015 — Certified Quality Management System covering all manufacturing and quality assurance processes.
- ISO 13485 — Medical device quality management system certification for products used in medical applications.
- EN 10204 3.1 — Third-party material test certificates provided with every shipment.
- ASTM A269 / ASTM A213 — Compliance with standard specifications for seamless and welded austenitic stainless steel tubing.
- ASME SA-213 — Compliance for tubing used in heat exchangers and pressure-containing applications.
- RoHS & REACH — Full compliance with European environmental and hazardous substance regulations.
- Biocompatibility Testing: ISO 10993-1, -5, -10, and -12 testing available upon request for medical-grade applications.
Note: Custom specifications, including non-standard OD/wall thickness combinations, special finishes, custom coil configurations, and batch-specific testing are available. Contact Wenzhou Jixing Metal Materials Co., Ltd. for a detailed quotation and technical consultation tailored to your specific application requirements.