[lincpimp]

6061 is not too bad to tap, but cutting oil for al is a must. I have not tapped too much 7075, but found it harder to do.

I usually use my benchtop drill press, clamp the item in the small vise, and turn the press pulley by hand while feeding the tap into the hole. Perfect cuts everytime, and the vise helps to keep the threads straight and true. Plus I have never broken a tap this way. Eevn a cheap small drill press works great, I am using a small craftsman unit right now.