Stainless Steel Capillary Coil Tube (Φ0.5mm – Φ3mm) for Precision Instrumentation
Product Overview
Wenzhou Jixing Metal Materials Co., Ltd. offers a premium range of stainless steel capillary coil tubes with outer diameters ranging from Φ0.5 mm (0.020 in) to Φ3.0 mm (0.118 in). Engineered to the highest standards of dimensional precision and surface integrity, these capillary-grade coil tubes are designed for demanding applications in chromatography, microfluidics, precision instrumentation, and medical devices. Delivered in continuous coil form, these tubes provide maximum material utilization and ease of integration into automated fabrication and assembly processes.
Material & Properties
Capillary coil tubes are manufactured from high-purity austenitic stainless steel grades, primarily SUS 304 (UNS S30400) and SUS 316L (UNS S31603), selected for their exceptional corrosion resistance, biocompatibility, and mechanical reliability under extreme operating conditions.
- Corrosion Resistance: Superior resistance to acids, alkalis, chlorides, and high-temperature oxidation
- Mechanical Strength: High tensile strength with excellent ductility, enabling reliable cold working and forming
- Biocompatibility: Fully compliant with medical-grade requirements for implantable and patient-contacting devices
- Surface Finish: Available in polished, electropolished, and passivated finishes with surface roughness as low as Ra 0.1 μm
- Temperature Range: Operational from cryogenic temperatures up to 870 °C (1,598 °F) depending on grade
Specifications
| Parameter | Specification |
|---|---|
| Product Name | Stainless Steel Capillary Coil Tube |
| Outer Diameter (OD) | Φ0.5 mm – Φ3.0 mm (0.020 in – 0.118 in) |
| Wall Thickness | 0.05 mm – 0.5 mm (0.002 in – 0.020 in) |
| Material Grades | SUS 304, SUS 304L, SUS 316, SUS 316L, SUS 321 |
| Manufacturing Process | Seamless (Precision Cold Drawing) |
| Surface Finish | Polished / Electropolished / Passivated (Ra ≤ 0.25 μm) |
| Coil Inner Diameter (ID) | Φ100 mm – Φ300 mm (3.94 in – 11.81 in) |
| OD Tolerance | ±0.01 mm (±0.0004 in) |
| Wall Thickness Tolerance | ±0.005 mm (±0.0002 in) |
| Roundness | ≤ 0.005 mm |
| Straightness | ≤ 1.0 mm/m |
| Delivery Form | Continuous Coil (Protective Packaging) |
| Standards | ASTM A269, ASTM A213, GB/T 12771, EN 10216-5 |
Manufacturing Process
Precision Seamless Cold Drawing
- Raw Material Selection: Vacuum-arc remelted (VAR) or electro-slag remelted (ESR) ingots ensure ultra-low impurity levels and consistent metallurgical composition.
- Hot Rodding & Annealing: Billet is hot-rolled into precision bar stock and subjected to solution annealing to achieve uniform austenitic microstructure.
- Piercing & Hot Extrusion: Initial tube blank is produced via rotary piercing or hot extrusion, establishing the base geometry.
- Multi-Stage Cold Drawing: The tube is progressively drawn through a series of precision tungsten carbide and diamond dies, reducing OD and wall thickness to target dimensions with extreme accuracy. Intermediate annealing cycles prevent work hardening.
- Final Annealing & Pickling: Solution annealing at 1050–1100 °C (1,922–2,012 °F) followed by controlled cooling eliminates residual stresses and restores full corrosion resistance.
- Surface Finishing: Electropolishing removes the top 3–5 μm of material, eliminating surface contaminants and achieving mirror-like finish. Final passivation treatment forms a stable chromium oxide protective layer.
- Precision Coiling: Tubes are wound onto precision coils with controlled tension to prevent deformation, kinking, or ovality.
- Quality Inspection: 100% dimensional verification using laser micrometers, ultrasonic wall thickness gauging, and hydrostatic pressure testing.
Applications
These capillary-grade stainless steel coil tubes serve as critical components in a wide array of high-precision industries:
- Chromatography Columns: GC (Gas Chromatography) and HPLC (High-Performance Liquid Chromatography) column tubing requires ultra-smooth inner surfaces and precise bore dimensions to ensure accurate separation and minimal dead volume.
- Microfluidics Systems: Lab-on-a-chip devices and microfluidic channels demand tubes with micron-level dimensional accuracy and contamination-free interiors for reliable fluid transport at micro-scale volumes.
- Precision Instrumentation: Analytical instruments, mass spectrometers, flow meters, and pressure transducers utilize capillary tubes for sample introduction, gas delivery, and fluid metering with exceptional repeatability.
- Medical Catheters & Needles: Surgical and diagnostic catheters, infusion devices, and hypodermic needles require biocompatible, corrosion-resistant tubing with smooth lumens to minimize patient trauma and ensure long-term reliability.
- Semiconductor Equipment: Ultra-clean gas delivery lines and chemical vapor deposition (CVD) systems benefit from the purity and smoothness of electropolished capillary tubing.
- Pharmaceutical & Biotechnology: Sterile fluid transfer, filtration housings, and bioreactor monitoring systems utilize capillary tubes for contamination-free processing.
Unique Selling Points
Ultra-Precision Capillary Manufacturing: Wenzhou Jixing Metal Materials delivers capillary tubes with OD tolerances as tight as ±0.01 mm and wall thickness tolerances of ±0.005 mm — performance benchmarks that meet the most stringent requirements in analytical and medical applications.
- Exceptional Surface Quality: Electropolished finishes with Ra ≤ 0.1 μm ensure minimum flow resistance and maximum cleanliness in chromatographic and microfluidic applications.
- Full Traceability: Every coil is accompanied by mill test certificates with full chemical composition, mechanical property data, and heat number traceability.
- Custom Dimensional Capabilities: Special OD and wall thickness combinations can be manufactured to customer specifications within the capillary range.
- Consistent Coil Quality: Precision coiling ensures zero ovality, no kinks, and uniform tension — reducing waste and improving downstream processing efficiency.
- Wide Grade Selection: Multiple stainless steel grades available to match specific corrosion, temperature, and biocompatibility requirements.
Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd. maintains rigorous quality management systems and holds the following certifications to assure product conformity and manufacturing excellence:
- ISO 9001:2015 — Quality Management System Certification
- ISO 13485:2016 — Medical Device Quality Management System
- ISO 14001:2015 — Environmental Management System
- EN 10204 3.1 — Third-Party Inspection Certification for Materials
- ASTM — Compliance with ASTM A269, A213, and related standards
- CE Marking — European Conformity for medical and industrial applications
- RoHS & REACH — Compliance with hazardous substance restrictions
All products undergo comprehensive testing including chemical analysis (OES), mechanical testing (tensile, hardness), dimensional inspection, hydrostatic pressure testing, and surface finish verification prior to shipment. Batch-level traceability is maintained throughout the entire production chain.