Internal Surface Finishing of Capillary Tube

Super surface finishing service for polishing inner surface of capillary tube

What is surface finishing?

Surface finish, also known as surface texture or surface roughness, refers to the texture and quality of an external surface of a manufactured item. It's a measure of the microscopic deviations in the surface's geometry, which can significantly impact the functionality, performance, and appearance of a component. The surface finish is an essential factor in manufacturing and engineering, as it can affect the mechanical behavior of parts, including friction, wear, light reflection, heat transmission, ability to distribute and hold lubrication, and fatigue resistance.

Surface finishes are usually characterized by roughness indicators, such as average roughness (Ra), root mean square roughness (Rq), and maximum roughness depth (Rz), among others. These measurements can be carried out using various methods, including touch stylus profilometers, optical methods, or atomic force microscopy, depending on the precision required and the nature of the surface.

Improvements in surface finish can be achieved through different manufacturing processes or finishing procedures such as machining, grinding, polishing, lapping, honing, and coating. The appropriate level of surface finish depends on the part's application; for example, a high level of smoothness may be required for components that need to reduce friction or seal effectively, while less critical applications may allow for a rougher finish.

Manufacturers specify the surface finish requirements for parts based on their application and performance criteria, typically referring to standardized surface finish scales and symbols according to national and international standards (e.g., ASTM and ISO).

What is surface roughness?

Surface roughness, often considered synonymous with surface finish, specifically refers to the irregularities on the surface of a material that result from the manufacturing process or wear over time. It's a component of surface texture, which includes the overall feel, appearance, and functionality of the surface, but surface roughness focuses on the measurable unevenness or deviations from an ideal flat plane

What sizes capillary tube can do internal surface finishing?

We focus on mini diameter tube surface treatment. Inner diameter from 0.05mm to 3.00mm

Type of capillary tube can use internal surface finishing service

If you have other materials, please contact us for evaluation.

Metal capillary tube

Ceramic capillary tube

PEEK capillary

Glass capillary tube

The capillary tube internal surface finishing standard

Materials	Tube inner diameter	Tube length	Surface roughness (Ra um)	Tolerance
Capillary tube	0.05mm - 0.1mm	500mm	Ra 0.1	±0.01mm
Capillary tube	0.1mm-0.2mm	400mm	Ra 0.1	±0.01mm
Capillary tube	0.2mm-0.3mm	200mm	Ra 0.02	±0.01mm
Capillary tube	0.3mm-2.0mm	500mm	Ra 0.01	±0.02mm
Capillary tube	2.0mm - 3.0mm	500mm	Ra 0.04	±0.03mm - xxx

Illustration for internal surface finishing of capillary tube

There are 6 steps for surface treatment

24 surface finish processes assure capillary tube quality

No.	Processes	No.	Processes
1	Capillary cutting 200 - 500mm length	13	Washing internal surface 3
2	Internal surface deburring	14	Flushing
3	Washing internal surface 1	15	External buffing
4	Tip grinding 1	16	Washing internal surface 4
5	Tube diameter reducing	17	Super surface finishing
6	Tube bending	18	Washing internal surface 4
7	Tip grinding 2	19	Drying 1
8	Tube extending	20	Nano coating
9	Tube welding	21	Drying 2
10	Internal surface fine polish	22	Inspection
11	Washing internal surface 2	23	QC
12	Airslot making (if necessary)	24	Packaging

Compare before and after surface finish

Before
Ra 1.6 surface finish

After
Ra 0.009um surface finish

Before
surface roughness 3.2

After
Ra 0.007um surface finish

How to measure surface finish?

Surface roughness measurement: ZYGO Newview System

Model: 5032

Surface roughness testing

convert surface finish: 1nm = 0.001um ; Ra 1.5nm = Ra 0.0015um

Position	1	2	3	Surface roughness average (Ra)
External surface	67.1nm	51.4nm	58.4nm	59.0nm
Internal surface	1.5nm	1.5nm	1.4nm	1.5nm

Zoom 200X view surface finish and calculating surface roughness

How to order an internal surface finishing service for your capillary tube?

If your capillary tube want to has a super surface finishing, please fill out below form, send email to info@finishingsurface.com, or chat with WhatsApp or WeChat