M2 × 0.4 tap drill size
1.60 mm drill — or 1/16 (0.0625 in) = 79% thread
M2 coarse series, 0.4 mm pitch. Tap drill Ø = nominal − pitch = 2 − 0.4 = 1.60 mm (≈77% thread, the standard chart value).
| Drill | Size | Thread % |
|---|---|---|
| 1.60 mm | 0.0630 in | 77% |
| 1/16 (inch) | 0.0625 in / 1.59 mm | 79% |
Rounding to your nearest stock drill moves the thread percentage only a few points. Cut taps only — roll-form taps need a larger hole. Verify before you cut.
Need a different thread percentage? Open the tap drill calculator · Metric tap chart · All calculators