Calculate Drill Size for Tap Diameter, TPI, and Thread depth.

Fill in common bolt sizes: (including # gage, fractional and metric) or enter:
Tap Major Diameter (Tmd) = / in or or
in mm (Tmd)
Threads per Inch (Tpi)
Percent of Thread (%T)
Ideal Drill Size = Tmd - (2*(0.64952/Tpi)*%T)
in mm

For more information:

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