Take your time and keep the tool straight. Make sure you use a good power drill when going this route. I cut holes in a head not thinking it could be a pilot effect. It wasn't a good idea to do this, plus there would be less tapping material if I waited to thread. Oh, using cutting fluid really helped keep the tool sharp and cool. The tool can be used without much machining experience if the pilot has an unthreaded bore and lubrication is used. Hopefully someone else isn't as naive as I am, but now I know better.