5/16" x 36 tpi...

[BCB]

What size drill bit do I use for that tap...

I can find info on 18 tpi (F) and 24 tpi (I), but not 36 tpi...

Will the "I" bit work as I have been using a 17/64" and it seems to work O.K.

But, I was wonder what the actual size bit might be for the tap size...

Thanks...BCB

[William Yanda]

I googled that-found Amazon selling a letter "L" bit for that purpose.

[country gent]

Look in the machinists hand book. It may list it outright or it gives a formula to calculate tap drill size. Another is to Look at tap makers websites they may have a chart that gives the Tap Drill for 75% threads.

[HATCH]

https://www.physics.wisc.edu/ishop/tapdrillchart.html

[Billthomas]

Tap dia. minus the reciprocal of the pitch

[M-Tecs]

19/64"