M30 × 2 tap drill size

28.00 mm drill — or 1-7/64 (1.1094 in) = 70% thread

M30 fine series, 2 mm pitch. Tap drill Ø = nominal − pitch = 30 − 2 = 28.00 mm (≈77% thread, the standard chart value).

DrillSizeThread %
28.00 mm1.1024 in77%
1-7/64 (inch)1.1094 in / 28.18 mm70%

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.