How to Choose CNC Router Bits
Choosing the right bit is one of the most fundamental yet error-prone steps in CNC machining. An unsuitable bit not only compromises part quality but can also cause breakage, burning, or even spindle damage. This guide breaks down the selection logic into five aspects: geometry, coating, flute count, shank size, and material compatibility.
1. Bit Geometry: Match the Feature
Different tasks require different cutter shapes. Below are the most common types and their applications:
| Bit Type | Visual Feature | Best For |
|---|---|---|
| End Mill | Flat bottom, spiral flutes | Roughing, contour cutting, surfacing |
| Ball Nose | Hemispherical tip | 3D relief, curved surfaces, chamfering |
| V‑Bit | V‑shaped tip (30°, 60°, 90°) |