Ignoramus10114 wrote:

I have an aluminum heatsink that I need to tap , I wanted to know if I
should use 6-32 or some less coarse thread like 8-32 would be better?
6-32 works fine. I do these often. A good, sharp tap (not the horrors from
the local hardware store) work quite well. I use "Alum-Tap" from Wibro as a
tapping fluid, it is incredible stuff. Makes the tap go in like it was
already threaded.

Jon