Quote Originally Posted by jonbabbz View Post
Do I need to use a taper tap first or can I just use a middle tap on Ali profile? Thanks
If you are just doing a few tapped holes in an aluminium pofile then a straight flute tap will do the job and is cheaper than a sprial flute, but if you are doing a lot of tapping the spiral tap is the way to go.
There are also special auto reversing patting attachments you can get that reverses the chuck when you lift the pressure off.
A little cutting fluid will help too.