The Steamboating Forum

Check out https://www.speedtaps.com/. These are taps made for use in an impact wrench. Haven't used them myself so I can add no more to what they say.
Dave

Couldn't help but notice the comparison:

On the left, an overweight guy with beard and tattoos struggles with a conventional tap wrench, on the right a blonde babe using the speedtap like a pro. Pretty (pun intended) advertising ploy that is a bit too obvious.

Ya, Fred the demo was a bit over the top. This is the one I wanted to post, but couldn't find at the time: https://www.youtube.com/watch?v=96LwwycOhPI
I little more down to earth from a guy down under.

Dave

They look more like a second cut, than a first. Look to do the job though.

Impact gun on a very brittle tap.. That would be like using an air chisel to drive a broach. It could work until something binds and then ''tick''.

-Ron

I prefer the first video. Not so hot on the head banger music.

I've had production jobs where I had to tap hundreds of 5/16" holes in 1/4" 6061 aluminum. Used a two flute spiral point tap with no lube and I still have the tap. Used a hand held electric drill.

Of course high strength aluminum is about the easiest stuff to tap that there is.

As I've commented before, it helps to go oversized on the drill size. 50% thread engagement is fine. The strength penalties compared to the standard 70% are minor. Unless you tapping into warm butter the bolt will fail before it will strip out usually.