M16 × 1.5 tap drill size

14.50 mm drill — or 37/64 (0.5781 in) = 68% thread

M16 fine series, 1.5 mm pitch. Tap drill Ø = nominal − pitch = 16 − 1.5 = 14.50 mm (≈77% thread, the standard chart value).

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