M4 Tap Drill Size and Drill Bit for M4 Thread
Use a 3.3mm drill bit
M4×0.7 · 0.1299 in / 3.3 mm · ~75% thread
M4 is a small metric thread used in electronics and small hardware. The tap drill is major minus pitch: 4.0 minus 0.7 equals 3.3 mm.
At a glance
| Tap drill | 3.3mm |
|---|---|
| Inches | 0.1299 in |
| Millimetres | 3.3 mm |
| Major diameter | 4 mm |
| Pitch | 0.7 mm |
| Fine pitch | M4×0.44999999999999996 → drill 3.55 mm |
Why this size
drillØ = major − pitch = 4 − 0.7 = 3.30 mm → tap drill 3.3mm
3.4 mm gives a slightly lighter thread. The standard M4 tap drill is 3.3 mm.
Related sizes
Compare with adjacent threads – coarse, fine and the opposite measurement system: