Tapping Torque

Tapping torque rises steeply with diameter and pitch — it is the usual reason small taps snap. Use this to sanity-check a tapping head or to judge whether a hand tap is realistic.

Empirical estimate calibrated so M8×1.25 in steel lands near 10 N·m. Tap geometry, coating, hole size and lubricant change this a lot — treat it as a first cut, not a spec.