Microholes make it possible to move a small amount of fluid, direct a beam, or distribute suction through an extremely compact component. However, making the opening small is only part of the challenge. The hole also needs the right depth, shape, location, and surface condition to do its job.

This spotlight takes a closer look at microholes and the design details that help turn an extremely small opening into a practical manufactured feature.

What Are Microholes?

Microholes are very small openings whose dimensions are commonly discussed in micrometers, or microns. One micron equals 0.001 mm. For perspective, a hypothetical 50-micron hole measures just 0.05 mm across.

The term does not describe one manufacturing process or one universal size limit. A microhole might be a short opening through a thin plate, a deeper passage in a metal component, or one feature in a closely spaced array. Each design presents a different manufacturing problem.

Where Are Microholes Used?

Potential applications include dispensing components, flow restrictions, optical apertures, filter plates, and suction fixtures. These examples share a need to control what passes through an opening. Their acceptance requirements can still differ considerably.

For instance, a beam aperture may place particular emphasis on opening geometry and edge condition. A fluid component may also need functional flow testing. A suction plate may require consistent hole distribution across an entire working area. Tell us what the feature needs to accomplish, along with its dimensions.

Five Details That Define a Microhole

• Depth: The length of the hole relative to its diameter affects process selection and access.
• Taper: Entrance and exit diameters may differ. That difference can be intentional or limited by the drawing.
• Pattern: Hole count, spacing, and position determine how an array fits into the component.
• Edge quality: Burrs, debris, or excessive edge rounding can interfere with the intended opening.
• Inspection: The measurement plan needs to address the actual acceptance criteria, including features hidden inside the part.

These requirements should be reviewed together. A minimum diameter by itself does not establish that a particular material, depth, tolerance, and quantity can be manufactured as a combination.

Explore the Microhole Design Guides

Start with the detail that matters most to your part:

• High aspect ratio microholes: understand hole depth and diameter before requesting a quote.
• Microhole taper: define straight and tapered openings without leaving the bore shape to interpretation.
• Microhole arrays: specify pitch, hole position, and open area for multi-hole components.
• Microhole burrs and edge quality: describe acceptable entrances, exits, and cleanliness.
• Microhole inspection: connect each critical requirement to a practical verification method.

How Are Microholes Manufactured?

Mechanical drilling, electrical discharge machining, and laser processing offer different ways to create small openings. The appropriate route depends on the material, geometry, and finished-part requirements. Some components also require additional finishing or cleaning after the hole is formed.

Our existing micromachining services, micro EDM, and laser micromachining pages explain those broader capabilities. For a microhole project, the next step is to review the complete feature rather than choose a process solely from a published minimum size.

What Should You Include in a Microhole RFQ?

A dimensioned drawing is the best starting point. Include the material and condition, hole diameter, thickness or depth, and quantity. Then identify critical tolerances, the required entrance and exit geometry, and any restrictions on burrs or surface condition.

For a pattern, provide the hole count and datum-based locations. For a functional opening, explain the operating conditions and any flow or other performance test. Also identify the inspection records and material documentation your project requires.

Frequently Asked Questions About Microholes

How small can a microhole be?

The practical minimum depends on the process, material, depth, and acceptance requirements. A demonstrated feature size on one sample should not be treated as a guaranteed capability for every component. Send your drawing for a project-specific review.

Can a small opening be made through a thick component?

It may be possible, but depth relative to diameter is a key consideration. Review our guide to high aspect ratio microholes before setting the depth and tolerance requirements.

In Need of Custom Microholes? Let Us Help.

Upload your drawing, material, and target quantities. Tell us which hole features are critical to performance so we can coordinate a manufacturing review and discuss the next steps for your component.

• Upload your CAD file or drawing
• Review custom dimensions and material options
• Receive engineering support for your application