Quartz Glass Capillary Tubes
Quartz glass capillary tubes are fine-bore tubes drawn from fused quartz of 99.95–99.99% SiO₂. We draw them from 0.3 to 3.0 mm OD with bores from 0.05 to 1.5 mm, in round, square, D-shaped, grooved and multi-bore profiles, cut and end-polished to length or supplied on a continuous spool, with ID tolerance down to ±0.005 mm.
Capabilities
Size
OD 0.3–3.0 mm · ID 0.05–1.5 mm
Tolerance
±10% standard · ±0.005 mm high precision
Length
10–2000 mm · Continuous spool
Profiles
Round, square, D-shaped, grooved · Multi-bore, 2 to 10+ holes
Material
Fused quartz, 99.95–99.99% SiO₂ · 1100 °C continuous use
Finishing
Laser cut, end polished · Polyimide or acrylate coating
Gallery
Get a quartz capillary quote
Send the OD, ID, tolerance grade, length, profile and end finish, and we will confirm the drawing route and quote the tubes.
Standard Dimensions and Tolerances
| Parameter | Range | Standard tolerance | High-precision tolerance |
|---|---|---|---|
| Outside diameter | 0.3–3.0 mm | ±10% | ±0.005 mm |
| Inside diameter | 0.05–1.5 mm | ±10% | ±0.005 mm |
| Wall thickness | 0.05–2.0 mm | ±10% | ±0.01 mm |
| Length | 10–2000 mm, or continuous spool | ±1.0 mm | ±0.1 mm |
Choose the grade by what goes into the bore. On a 0.127 mm bore, ±10% allows ±13 µm, which is too loose to center a 125 µm optical fiber; fiber pigtails and fiber arrays need the ±0.005 mm grade. Chromatography columns and fluid lines usually work with the standard grade.
From Drawing to Finished Capillary
- 01
Draw to size
The tube is drawn from a fused quartz preform to the OD, ID and profile on your drawing. Below about 1 mm OD, the drawn tube is flexible enough to coil.
- 02
Coat if needed
A polyimide or acrylate coating protects the surface from scratches, so thin capillaries can be coiled, bent and handled without breaking.
- 03
Cut to length
Capillaries are laser cut or mechanically scored and broken, to lengths from 10 mm to 2000 mm.
- 04
Polish the ends
Ends are polished chip-free and optically clear for fiber insertion, light coupling and leak-free fluid connections.
- 05
Inspect
OD, ID and length are checked against the tolerance grade before packing.
Profiles and Bore Configurations
The profile follows the job the capillary does in your assembly.
Single round bore
The standard form for chromatography columns, fluid lines and capillary electrophoresis.
Square and rectangular
Flat walls let a camera or detector look through without the lens effect of a round tube, for microfluidic channels and flow cells.
Outer square, round bore
A round channel in a square body that seats flat in a fixture.
V- and U-groove
Open grooves that hold fibers in line for fiber arrays and pigtail alignment.
Multi-bore
Two to ten or more holes, in rows or in a flower pattern, for multi-fiber holders and parallel channels.
Custom outlines
Triangular, hexagonal, D-shaped, elliptical and eccentric profiles to your drawing.
Quartz Capillary Questions
Why quartz instead of glass capillaries?
Fused quartz runs continuously at 1100 °C, transmits UV, and is chemically inert, which is why it is used for gas chromatography columns and UV detection. Borosilicate capillaries cost less and suit lower-temperature work.
Coated or uncoated?
Coat the capillary when it must be coiled, bent or handled often. Polyimide is amber and absorbs UV, so where light must pass through the wall, for UV adhesive curing or a detection window, order it uncoated or with the coating removed over that section.
How much pressure can a capillary take?
It depends on the ratio of outside to inside diameter: a heavier wall around the same bore holds more. Send the bore and working pressure, and we will calculate the wall thickness.
What is the maximum temperature?
1100 °C in continuous service, with short excursions above that. Long holds above the continuous rating can devitrify the surface, so tell us the full temperature profile.
Can the ends be finished for fiber insertion?
Yes. Ends are polished chip-free and optically clear, and the bore entry can be finished for smooth fiber insertion.