Minimum hole diameter for 5-axis CNC machining
The smallest hole we guarantee in 5-axis CNC machining is 1 mm. Smaller holes are sometimes achievable after engineering review, but the risk of tool breakage and dimensional deviation rises sharply.
- Beyond diameter, the depth-to-diameter ratio matters most. Up to roughly 4× diameter a hole is routine; beyond that you need a long-reach tool, through-tool coolant or peck drilling, which adds machine time.
- In printing processes small holes close up from powder or resin residue: expect a few tenths of loss. If the hole is functional, specify it undersize and have it drilled or reamed afterwards.
- Threads have their own lower bound: M1.6 – M64, complex angles supported.
Frequently asked questions
- Should I print holes to size or ream them?
- For fits and bearing seats, always drill or ream. Produce the hole undersize and treat the critical dimension as a separate operation — the cheapest route to a reliable fit.
- How deep can a small hole be?
- Up to about 4× diameter is standard. Deeper is possible with adapted tooling and longer cycle time; mention it in your request so we price it correctly.