Thread: How do you tap parts in the lathe?

I generally use a soft faced hammer to tap parts in the lathe...

Originally Posted by .RC.

I generally use a soft faced hammer to tap parts in the lathe...

There's one in every crowd.......

Just a note on using a quality keyless chuck if a cheap one won't grip the tap. Mine is an LFA, not a cheapie at all and it still won't hold. No problem with drills though.

Got 2 sizes of these from CDCO, have used taps up to M14 in the bigger of the 2.

SP32-20120304-152632.jpg

Guess these are the same that Pete F uses.


Have also modified the small end of a Little Machine Shop die holder to take a ratchet type tap holder

Looks like I got just what I hoped for when I started this thread - lots of different tools and tricks to do the same job. And even better, so far it looks like a consensus could be made that my drill chuck is crap but I'm not alone! I can't even get it to hold while rotating the spindle by hand, so I've never bothered trying to power tap on the lathe, much as I'd like to (gotten into the habit of doing it on the mill, so much faster and lazier )

Might have to poke around in my stashes and see if I can dig up something to make a 'gizmo' inspired by all your ideas...

Originally Posted by simonl

I have never done threading on the mill. Would an ER collet work in the mill to tap or would it turn like the drill chuck?

ER32s work perfectly on my Bridgeport clone for power tapping (have done up to 12mm), I reckon there's a good chance I'd snap the tap before the collet slips.

I did some tapping today. The T-handle bar rests on the top-slide. Simultaneously turn chuck with left hand and tailstock wheel with right hand. If the bar on the T handle is too short to reach the top-slide, extend it with a piece of tube.

The T-handle in the pic is a Goliath brand. About 30 bucks.

The hard jaws of a chuck will not grip a hard surface, and taps seem to be hard all over. So, a softer metal shim wrapped around the tap will help get a real grip.
For taps with centre holes I use a dead centre in the tailstock and a normal tap holder. The diy type in 2 halves with 2 screws performs as good as the best for me. I turn the headstock chuck by hand, feeding the tailstock quill as I go, so it's a 2 handed operation. To prevent the tap from turning, I either clamp a bar in the toolpost for the handle of the tap holder to rest against and slide along, or use the surface of the compound slide itself, although this method tends to remove paint from it. (what paint?)

Jordan

Originally Posted by nadroj

For taps with centre holes I use a dead centre in the tailstock and a normal tap holder. The diy type in 2 halves with 2 screws performs as good as the best for me.

Jordan,
A few of my taps don't have centre holes in the rear end, so that type of tap handle doesn't work in the lathe with them. A T-handle with a centring hole in the back works with both types of tap.

You're right about scratching the paint.

Chris