M16 × 2 tap drill size

14.00 mm drill — or 35/64 (0.5469 in) = 81% thread

M16 coarse series, 2 mm pitch. Tap drill Ø = nominal − pitch = 16 − 2 = 14.00 mm (≈77% thread, the standard chart value).

DrillSizeThread %
14.00 mm0.5512 in77%
35/64 (inch)0.5469 in / 13.89 mm81%

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.