thread mill

[mielke]

What is the recomended drill size for a 3/8-16 thread mill. For a normal tap i know its 5/16" and I know a thread mill has more wiggle room as for the drill hole size. So is it recomended to use the 5/16" hole or does anyone advise differently?

 

[mrainey]

The minor diameter is the same for thread mills and cut taps. A form tap wants a minor diameter, before tapping, of 0.344

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