Precision Centering
Low runout supports accurate tool entry and hole placement.
Drills / Micro drills
Micro Drill Bits
What Are Micro Drills and How Do They Work?
Micro drills are specialized miniature cutting tools designed for intricate machining tasks where standard bits are too large. Operating at high RPM, these delicate tools rely on close concentricity to prevent breakage.
High-Speed Shearing
At high spindle speeds, the cutting lips shave microscopic layers of material.
Chip Evacuation
Engineered flutes draw tiny chips upward to prevent packing in microscopic cavities.
Thick-Shank Rigidity
A standardized, oversized shank fits machine collets securely and supports the tiny cutting diameter.
Key Features and Benefits of Micro Drill Bits
Ultra-Miniature Scaling
Supports small hole-size requirements in electronics and precision components.
Oversized Shanks
Typically uses a standard 1/8" or 3 mm shank for secure gripping in CNC collets despite the small cutting diameter.
Close Concentricity
Micrometer-scale grinding helps limit vibration and runout at high spindle speeds.
Rigid Web Construction
Supports the fragile tip against deflection and breakage under feed pressure.
Fine Surface Finish
Produces a fine internal finish that can reduce secondary reaming requirements.
Micro Drill Bits Specifications
| Specification | Range / Details |
|---|---|
| Diameter Range | 0.05 mm to 3.0 mm (Custom small drill sizes available) |
| Flute Design | Standard Spiral, Parabolic, or Straight Flute |
| Shank Diameter | Commonly standardized (for example, 1/8" or 3 mm) |
| Point Angle | 118°, 130°, or 135° Split Point |
| Tolerance | Ultra-precision ground to sub-micron accuracy |
| Operation Type | High-RPM CNC micromachining |
Materials and Coatings Available for Micro Drill Bits
| Material / Coating | Best For | Key Advantage |
|---|---|---|
| Solid Carbide | High-volume micromachining. | Provides rigidity to limit tool deflection and breakage at microscopic scales. |
| Cobalt (HSS-Co) | Tough alloys and manual jeweler operations. | Offers more flex than carbide, reducing snap risk in less rigid setups. |
| TiAlN Coating | Dry cutting and high-temperature alloys. | Reduces friction so microscopic chips can move through the flutes without packing. |
Solid carbide provides rigidity for high-volume micromachining, cobalt HSS adds flexibility for less rigid setups, and TiAlN reduces friction in dry cutting and high-temperature alloys.
Which Machines Use Micro Drills?
CNC Micro-Machining Centers
High-speed, low-vibration machines designed for sub-millimeter precision.
Swiss-Type Lathes
Support high-volume production of microscopic cylindrical medical and aerospace parts.
Precision Drill Presses
High-RPM, sensitive manual presses used in watchmaking and fine jewelry.
Applications and Industries for Micro Drill Bits
Printed Circuit Boards (PCBs)
Bores via holes for electronic connections while limiting delamination of fiberglass boards.
Medical Devices
Machines microfluidic channels and precision ports in surgical instruments and implants.
Horology (Watchmaking)
Creates microscopic pin and gear holes for mechanical watch movements.
Fuel Injectors
Machines precise automotive and aerospace fuel-nozzle spray holes with micro tooling.
Frequently Asked Questions About Micro Drill Bits
What is the smallest drill bit size Bauron offers?
The supplied standard range includes diameters down to 0.05 mm. Bauron can review smaller custom diameter requirements for a specific micromachining application.
Why do micro drills have such thick shanks?
The cutting tip may be a fraction of a millimeter, while the shank remains at a standard size such as 1/8 inch or 3 mm. This allows secure holding in precision CNC collets and provides rigidity for the fragile cutting tip.
Can I use micro-size drill bits in a handheld rotary tool?
Handheld use is discouraged for true micromachining, especially with brittle solid-carbide bits. Small movements, vibration, or off-axis pressure can snap the bit, so a rigid stationary machine is recommended.
How do I prevent micro drills from breaking?
Use a rigid machine with minimal spindle runout, pecking cycles for chip clearance, suitable cutting fluid to reduce friction, and feed and speed values appropriate to the workpiece material.
Can Bauron manufacture custom micro tooling?
Bauron can review custom micro drills with application-specific flute lengths, tip geometries, and coatings for aerospace, medical, or electronic components.
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