Custom Micro-Bore Quartz Capillaries

Parameter	Factory Standard	Manufacturing Limit
OD	0.5–5 mm	—
Minimum bore	0.1 mm	Down to 0.05 mm on request
Bore tolerance	±0.01 mm	±0.005 mm, confirmed per order
Concentricity	≤10% of wall	Tighter, confirmed per order
Length	10–500 mm	—
Straightness	≤0.5 mm/m	—

Inquiry

Micro-bore quartz capillaries provide small, continuous channels for low-volume analytical connections, fine dispensing and flow restriction. Specify the usable open bore through the finished length, as well as its nominal diameter.

What Changes Below 0.10 mm Bore ID

Below the standard 0.10 mm minimum, a bore-size callout alone is insufficient to define an acceptable part. Establish how the channel will be inspected, the usable length and the permitted end condition before choosing a tighter limit. The 0.05 mm option is custom development requiring drawing review, sample validation and agreed inspection, rather than a standard stock size.

Bore Continuity and Blockage Control

An acceptable cross-section at the end face does not by itself prove that the entire channel is open. Cutting debris, edge chips or local deformation can obstruct a fine bore. Specify whether acceptance requires an optical continuity check, a flow check or another agreed method, and identify the cleaning and end-protection requirements for delivery.

ID, OD and Concentricity Trade-Off

Choose the OD for handling, support and the mounting interface; choose the ID for the required fit or flow area. Define bore position separately where the outside is an alignment datum. Review this combination with finished length and inspection access, especially for a custom sub-0.10 mm bore. For flow restriction, include the fluid and operating conditions so bore-size variation can be assessed against the required function.

Micro-Bore Control

The Bore Must Be Sized, Open and Centered

Controlled Feature	Reference Capability / Requirement
Bore ID	Ø0.10–0.30 mm industry-reference rangeMinimum ID must be confirmed against OD, length and inspection method
ID Tolerance	Reference ±0.01 mm
Outer Diameter	Ø0.5–5 mm reference envelope
Concentricity	Bore position relative to the OD or functional datum
Bore Continuity	Open channel verified through the finished cut length
Finished Length	Specified with straightness only where feeding or alignment requires it
End Condition	Clean cut / ground / chamfered without closing the micro-bore
Packaging	Ends protected and clean packed to reduce particle entry and blocked channels

Bore Selection

Choose the Smallest Bore the Function Actually Needs

Reference ID	Design Priority	Typical Use
Below Ø0.10 mm · custom development	Bore continuity, inspection and clean handling	Microfluidic restriction, fine dispensing and analytical flow
Ø0.15–0.20 mm	Concentricity and controlled cut ends	Chromatography interfaces, small sensors and fluid dosing
Ø0.25–0.30 mm	Fit, flow area and repeat assembly	Medical components, ink delivery and compact fluid routing

Delivery Forms

Micro-Bore Parts Protected from Cutting to Assembly

Straight Micro-BoreContinuous precision channel through a cut quartz length

Protected Micro-BoreLarger OD around the small channel for stiffness and handling

Chamfered EntryDefined lead-in without closing or chipping the bore edge

Clean Finished EndsGround faces and protected packaging for inspection and assembly

Applications

Where Flow Area Is the Critical Dimension

MicrofluidicsFixed quartz channels for metering, restriction and compact fluid routing

Inkjet & Fine DispensingSmall continuous bores for controlled delivery and nozzle interfaces

Chromatography & AnalysisLow-volume connections between columns, detectors and analytical cells

Medical ComponentsSmall-bore quartz elements where cleanliness, fit and open-channel verification matter

Need a verified open micro-bore?Send target ID, tolerance, OD, finished length, concentricity and cleaning or packaging requirement.

Open the Capillary Configurator

Engineering Data

Grade-Qualified Material Purity

Electric-fused / flame-fused quartz: SiO₂ ≥99.99%; synthetic JGS1-grade fused silica: ≥99.999%. Grade and lot certificate govern supplied material.

Engineering Data

Service Temperature

Transparent quartz: continuous use ≤1100 °C; short-term excursions ≤1200 °C. Opaque / milky quartz: continuous use ≤1000 °C. Load, atmosphere, support span and thermal cycling determine the application limit.

Standard minimum bore is 0.10 mm. A 0.05 mm micro-bore is a custom development specification subject to drawing, sample validation and agreed inspection, rather than a stock-size promise.