🇺🇸 US edition · Metric and US customary unitsPrecision engineering calculators & references
Fasteners

Tap Drill Calculator

Find an approximate metric tap drill from major diameter and thread pitch.

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About this calculation

Find an approximate metric tap drill from major diameter and thread pitch. This page gives the formula, a direct calculator and practical context so the result can be checked rather than treated as a black box.

Common mistakes

Mixing units, using nominal rather than measured dimensions, omitting efficiency or friction factors, and applying theoretical results without an appropriate safety factor are the most common errors.

Useful equipment

Find a tap and die set on Amazon US.

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