If you need a high‑precision, durable tube for fluid or gas control, Jianglin delivers stainless steel capillary tubes that meet tight tolerances and high standards. We design and manufacture these tubes with precision in mind. Moreover, we customize length, diameter, surface finish, and grade (such as 304 or 316L) to fit your specific needs.

In this blog, I’ll walk you through the basics, key benefits, manufacturing steps, applications, and how Jianglin stands out as your supplier.

What Is a Stainless Steel Capillary Tube?

A stainless steel capillary tube features a small outer diameter and a narrow internal passage—often between 0.1 mm and 3 mm—built to maintain consistent dimensions along its entire length. Because it behaves like a tiny blood vessel, this capillary structure enables precise, controlled fluid flow with minimal variation.

Typically seamless, these tubes withstand heat, pressure, and aggressive chemicals. At Jianglin, we stock thousands of meters in various grades, including 304 and 316L, and we cut to exact customization as requested by clients.

Why Stainless Steel Capillary Tubes Matter

Precision & Tight Tolerances

Engineers need reliable, consistent tubing for chromatography, instrumentation, and medical use. Stainless steel capillary tubes deliver unmatched precision. Their tight dimensional tolerances ensure accurate fluid delivery or gas transmission. They also prevent sample contamination or measurement errors, especially in sensitive applications like HPLC and gas analysis.

Corrosion Resistance & Cleanability

Stainless steel resists rust and chemical attack thanks to chromium content above 11%, forming a self‑healing passive layer. Whether in humid, acidic, or saline environments, these tubes maintain integrity. Plus, they clean easily without reacting with cleaning agents—ideal for medical, pharmaceutical, or food‑grade systems.

High Strength and Durability

Even though they appear slender, stainless steel capillary tubes maintain tensile and yield strength similar to structural components (over 500 MPa tensile strength in typical grades). They resist deformation under pressure or bending and last longer than softer metals or polymers. As a result, you reduce maintenance and downtime while boosting overall system reliability.

Wide Temperature Range

These tubes perform at cryogenic temperatures up to elevated levels—304 and 316 alloys handle harsh thermal conditions without degrading. That makes them suitable for aerospace fuel lines, hydraulic systems, and thermal sensors.

Manufacturing: How Jianglin Produces High‑Quality Capillaries

At Jianglin, we follow a thorough, precision-driven process:

Step 1: Grade Selection

We evaluate your application and recommend appropriate stainless grade—304 for general corrosion resistance and affordability, or 316L for extra chemical and chloride resistance.

Step 2: Tube Drawing & Forming

We start with cold or hot forming. After welding (if needed), we draw tubes to precise diameters. Then we stretch or shrink them to achieve exact outer diameters, wall thickness, and smooth inner surfaces.

Step 3: Heat Treatment & Annealing

We anneal each tube to relieve internal stress and restore ductility. That step improves mechanical performance and prevents brittleness, especially after drawing.

Step 4: Surface Finishing & Passivation

Then we polish, passivate, or even electropolish the tubes to enhance corrosion resistance and surface cleanliness. That process removes impurities, oils, or particles that might affect sample integrity.

Step 5: Quality Control

We test dimensional accuracy with high‑precision instruments and inspect each tube for surface defects. We also ensure performance under pressure or chemical exposure, following strict standards like ASTM and JIS.

Common Applications of Stainless Steel Capillary Tubes

Jianglin serves diverse industries. These tubes appear in many critical systems:

Medical & Diagnostic Equipment

We supply capillary tubes used in blood analyzers, catheters, drug delivery systems, and surgical instruments. Their biocompatibility, sterilizability, and fine diameter make them ideal for medical use.

Chromatography & Laboratory Systems

Analytical instruments such as HPLC, UPLC, viscometers, and gas analyzers rely on ultra-small internal diameter tubing. Our seamless capillaries minimize band broadening and ensure reproducible readings.

Automotive & Aerospace Controls

We supply tubes for fuel injection, brake lines, hydraulic circuits, and instrumentation in aircraft. These components demand high pressure, extreme temperatures, and resistance to vibration—areas where capillary tubing excels.

Refrigeration & HVAC Systems

Capillary tubes regulate refrigerant flow between evaporators and condensers—maintaining proper cooling cycles efficiently and reliably.

Industrial Automation & Instrumentation

Pressure transmitters, flow meters, Bourdon gauges, pneumatic devices, and control systems use capillaries for precision fluid routing. Their reliability under industrial conditions matters significantly to safety and accuracy.

Benefits of Choosing Jianglin Capillary Tubes

We stand out in these ways:

• We craft seamless tubes with no welds, so grain structure stays consistent and strength remains uniform.
  
  

• We maintain tight dimensional tolerance (e.g. ±0.01 mm) and smooth bore surfaces, preventing sampling errors or turbulence.
  
  

• We stock a broad inventory in 304 and 316L, plus offer customized coil lengths, finishes, and dimensions with low MOQ (minimum 1 ton).
  
  

• We apply advanced polishing, passivation, or cleaning protocols to deliver clean tubing ready for hygienic environments.
  
  

• We uphold certifications (ASTM, EN, JIS), continuous inspection, and support from design through delivery.
  
  

Choosing the Right Tube: Key Considerations

When you select capillary tubes, pay attention to:

1. Material Grade: 304 works for general use; 316L handles chlorides or acidic conditions. Titanium‑stabilized 321 suits high‑temperature exposure.
   
   

2. Diameter and Wall Thickness: Choose outer/inner diameter and wall thickness according to fluid type, flow rate, and pressure. Jianglin supports sizes from 0.15 mm OD up to 15 mm, with walls from 0.05 mm to 1.5 mm.
   
   

3. Surface Finish: Electropolishing or passivation reduces friction and avoids contamination. That enhances performance in medical or analytical systems.
   
   

4. Quantity and Length: We deliver custom cut lengths, coil form, or batches as needed—good for prototype through high-volume runs.
   
   

5. Certifications & Testing: Confirm compliance with your industry standards and required quality benchmarks before ordering.
   
   

Jianglin Capillary Tube Success Stories

At Jianglin, a medical-device manufacturer partnered with us to supply stainless steel capillaries for a miniaturized blood analyzer. Thanks to our tight tolerances and surface cleaning, their system achieved consistent sample accuracy with zero contamination. Moreover, they reduced maintenance and calibration downtime.

In another case, an aerospace supplier used our 316L seamless tubing in hydraulic control lines. After extensive stress testing, they praised our long-term reliability in high‑pressure and high‑temperature flight conditions.

Summary & Next Steps

You deserve tubing that works reliably, safely, and accurately. Jianglin’s stainless steel capillary tubes meet every requirement:

• Precision-controlled dimensions
  
  

• Corrosion-resistant and hygienic design
  
  

• Seamless strength with consistent grain
  
  

• Multiple grades available (304, 316L, 321)
  
  

• Custom lengths, finishes, and surface treatments
  
  

• Strict quality control and global delivery
  
  

Whether for medical diagnostics, fluid analysis, aerospace hydraulics, or industrial instrumentation, pick the right tube—and choose Jianglin for both quality and service.

Call Us or Request a Quote

Contact our team to discuss your specifications. We deliver free samples, fast lead times, and tailored solutions. Get your custom stainless steel capillary tubes now and ensure performance you can trust.

We at Jianglin design with precision, manufacture with care, and deliver with confidence. Let’s build your next high‑precision system together.