Learned how to tap on a lathe today

It is kind of really amazing, how well I can tap on a manual lathe when I need a concentrically tapped hole. The accuracy and ease of that cannot possibly be even approached while tapping manually.

To hold the tap, I used Morse tapered tap collets that I horse traded a while ago. They are made to hold taps with square shanks. See mcmaster item 2731A49 for example.

It was also nice to slow down the lathe greatly, by changing the frequency of the VFD.

Reply to
Loading thread data ...

Must be nice to have a good lathe. I tapped something like that the other day by clamping a tap in the drill chuck for my tail stock and sliding the tail stuck up against the work piece and holding light pressure with my hand while bumping the lathe. Forget low speed. LOL.

Click/Click Click/Click Click/Click

Its pretty cool though to try something new and have it work isn't it.

Reply to
Bob La Londe

I've used a tool like this for many years:

formatting link
It has a 1/2" shank that fits the tailstock chuck in the lathe and the chuck in the mill. I crank the tap by hand, or stop the tap with a wrench and rotate the lathe chuck by hand. It preserves "feel" and enables "rocking" the tap to break chips, useful in some materials with some tap sizes.

Not a production approach to be sure. I don't do production. It works very nicely for model-shop sort of jobs and tasks.

Reply to
Don Foreman

Avoid using hand taps and you don't have to worry about backing the tap. Assuming you are tapping a through hole, there's nothing quite like a gun plug tap for power tapping. They're commonly referenced as spiral pointed taps. For blind holes, a spiral fluted tap serves the same purpose, as it lifts the chips from the hole instead of packing them in the flutes, which is the chief cause of tap breakage when power tapping by using straight flute taps not intended to be used under power.


Reply to
Harold & Susan Vordos

Plus, you can do weird things like making worm wheels with them:

formatting link

-- Jeff R.

Reply to
Jeff R.

I often do the same thing , but I use the lever on mine to lightly engage the belt drive . Drop it in back gear and away we go . If it stalls or the tap slips in the chuck , it's time to back it out and clear the chips .

Reply to

That is a bit dangerous for the tap and your work. You must have a torque release in case of bind. I use conventional hand taps and chuck with a standard 1/2' Jacobs drill chuck on the round shank. In case of bind, the shank will slip in the chuck. Steve

Reply to
Steve Lusardi

release in case of bind. I use conventional hand taps

case of bind, the shank will slip in the chuck.

I use the drill chuck until the tap has cut enough threads to stay straight, then switch to a hand tap wrench short enough to clear the lathe ways or mill column.

formatting link
have only 3" of quill travel and that type of wrench lets me leave the drill chuck in place.

I've just about used up the 9 lives power-tapping, but I still back it out with power.


Reply to
Jim Wilkins

Very cool!

Reply to
T.Alan Kraus

I tap shotgun muzzles for screw in chokes while under power in the lathe.

T Alan, how do you calculate the SPL in db reubar at the threshold of supersonic gas 2 atmospheres peak, cavitation trough?

You did it once before and I can't find it.

Reply to

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.