M8 × 1 tap drill size

7.00 mm drill — or J (0.2770 in) = 74% thread

M8 fine series, 1 mm pitch. Tap drill Ø = nominal − pitch = 8 − 1 = 7.00 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