M14 × 1.5 tap drill size
12.50 mm drill — or 31/64 (0.4844 in) = 87% thread
M14 fine series, 1.5 mm pitch. Tap drill Ø = nominal − pitch = 14 − 1.5 = 12.50 mm (≈77% thread, the standard chart value).
| Drill | Size | Thread % |
|---|---|---|
| 12.50 mm | 0.4921 in | 77% |
| 31/64 (inch) | 0.4844 in / 12.30 mm | 87% |
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