In article ,
"Robin S." wrote:

"Joseph Gwinn" wrote in message
...

I hadn't thought of using it for tapping. It ought to work, at least
for larger sizes.

The larger the tap, the greater the torque requirement (large at work is
M36). Could be difficult.

So far, I have not needed to go beyond 3/8-16 and M8-1.25, but I have a
few 1/2-13 taps ready to go.


If I can keep the tap properly aligned by hand. What
I've been using is a piloted tap wrench in the drill press.

You should try a spiral-point tap, in the drill chuck. Ideally your drill
press reverses to pull the tap out. Probably still faster than hand tapping
if you can only run the tap under power forwards.

I do use spiral-point taps, and gun taps, but only by hand so far.
Isn't 500 rpm a bit fast for a tap? How do you stop in time?

I have also been using a thread-forming 10-32 tap for some very deep
blind holes in aluminum. I had been using various kinds of cutting
taps, but it was touch-and-go, and I did break a few taps until
switching to thread-forming taps for this job. None of the broken taps
were Asian. Some were Greenfield, and some were Sossner (sp?).

Joe Gwinn