304 stainless steel capillary tube

Comprehensive analysis of stainless steel capillary tube
1、 Definition and structural characteristics
Stainless steel capillary tube refers to an extremely fine seamless pipe with a diameter of ≤ 6mm (usually ranging from 2-8mm in outer diameter and 0.1-2.0mm in wall thickness), named after its diameter as thin as hair, widely used in precision equipment and industrial protection fields. Its material is mainly austenitic stainless steel such as 316L and 304, which is formed through cold rolling/cold drawing process. The surface is polished (such as glossy or electrolytic polishing), and the smoothness can reach Ra ≤ 0.4 μ m 35.
2、 Core performance advantages
Physical characteristics
High flexibility: can be freely bent into any angle and curvature radius, with consistent flexibility in all directions, suitable for complex wiring demands23.
Strong tensile strength: The axial tensile force can withstand more than 6 times the nominal inner diameter, effectively protecting the internal circuit from external force damage.
Seamless structure: No weld defects, high compressive strength, suitable for high-pressure fluid or gas transportation.
Environmental resistance performance
Corrosion resistance: Contains over 12% chromium (Cr), forms a dense oxide film, and resists chemical media (such as acid, alkali, chloride) and marine environment corrosion.
High temperature resistance: The long-term working temperature range is -50 ℃~300 ℃, and it can withstand higher temperature environments in the short term.
Electromagnetic shielding: Provides excellent electromagnetic interference protection and is suitable for precision electronic equipment.
3、 Typical application areas
Domain application scenario performance matching reference source
Industrial automation instrument signal tube, sensor circuit protection tube, anti electromagnetic interference, wear-resistant 23
Medical equipment injection needles, surgical instruments, endoscope components biocompatibility, high cleanliness 37
Optical and electronic fiber optic internal support, miniature antenna, semiconductor equipment components with high dimensional accuracy (tolerance ± 0.02mm), and no impurity pollution
Energy and chemical heat exchanger tubes, corrosive medium transport tubes, high temperature resistance, chloride ion corrosion resistance 34
4、 Specifications and selection suggestions
Common parameters: outer diameter 2-8mm, wall thickness 0.1-2.0mm, length can be customized (standard 6m) 34.
Material selection:
304 stainless steel: High cost performance, suitable for ordinary corrosive environments (such as food and medical equipment).
316L stainless steel: containing molybdenum (Mo) to enhance corrosion resistance, suitable for harsh environments such as marine and chemical industries.
5、 Precautions
Processing limitations: To avoid excessive bending that may cause deformation of the pipe wall, it is necessary to use specialized bending tools for operation.
Cost control: 316L material is priced higher than 304, and 304 can be prioritized for non strong corrosion scenarios to reduce costs.
Stainless steel capillary tubes have become key functional materials in high-end industrial and civilian fields through precision manufacturing and diversified performance.