M3 Tap Drill Size and Drill Bit for M3 Thread
Use a 2.5mm drill bit
M3×0.5 · 0.0984 in / 2.5 mm · ~75% thread
M3 is a very small metric thread common in electronics and precision gear. The tap drill is major minus pitch: 3.0 minus 0.5 equals 2.5 mm.
At a glance
| Tap drill | 2.5mm |
|---|---|
| Inches | 0.0984 in |
| Millimetres | 2.5 mm |
| Major diameter | 3 mm |
| Pitch | 0.5 mm |
| Fine pitch | M3×0.25 → drill 2.75 mm |
Why this size
drillØ = major − pitch = 3 − 0.5 = 2.50 mm → tap drill 2.5mm
Use a sharp bit and light pressure on such a small thread. The standard M3 tap drill is 2.5 mm.
Related sizes
Compare with adjacent threads – coarse, fine and the opposite measurement system: