Thread form chart, helicoil, metric, NPT, cut/form taps

[CapriMikeC]

Since it comes up so often, attached is a chart for internal threads. Cut taps require different starting hole sizes compared to form taps.

Notice that nearly all have a lower and upper range for the drilled hole before tapping.

Screw Thread Inserts (STI) are industry standard helicoils.

Also available for download from https://dam.precisiontools.media/export/original/Emuge_Tap_Drill_Sizes_Wall_Chart.pdf