Drill Press Tap Adapters

[jjr2001]

One of the best ways to start a tap straight is to just tap it immediately after drilling the hole on the drill press.
Great for the drill press and Mini Mill when you have used a vise to hold the part.

I don't use these for power tapping but rather for manual tapping after drilling the hole on the drill press or mini mill. These adapters will allow you to manually (or with power) use the drill press chuck to hold your tap and at least to start the threads. I usually only start the taps with these adapters and then finish the thread with a standard tap wrench.

In operation I rotate the chuck for two full threads using a "tommy bar" in the chuck key holes of the drill press chuck. This along with mild pressure on the quill will be enough to start the threads and then remove the adapter and put the regular tap handle on the tap to finish up.
My small shop made tap handle fits well even on my mini mill. The drill press has enough depth to use the standard tap handle for final tapping.
Small Tap Handles or Tap Wrench

If you don't like the tommy bar idea in the chuck then just add a cross hole in each tapping adapter at the lower end of the shank near the flats then use the cross hole for the tommy bar. If you plan on adding the tommy bar holes you might want to make the shank end longer than the print dimensions. This is necessary especially for the smaller tap adapters that are quite short.

Note: Your tap shank diameters may differ so the exact diameter of the tap shank hole and the width of the slot may differ from the drawings. Use the closest drill available then use an emery rod or reamer to bring the hole to exact dimensions. A close slip fit for the shank and the square drive slot are recommended.

Drill the hole that will become the slot thru the entire part as the first step.

I did not find the magnets all that useful. If you do not install the magnets then the tap can easily be ejected using a rod from the shank end. They tend to stick in the adapter after tapping a few holes. Even if you install the magnets (Neodymium type) they can be punched out a later time it you need to remove a stuck tap.

Here are a few other tapping ideas and aids:
Power tapping tap holders
Tapping Set with chucks for or Mill Drill Press
https://www.homemadetools.net/homema...s-tapping-aids
Sensitive Tap Adapter
Lathe Die and Tap Holder
https://www.homemadetools.net/homemade-power-tapper-3

Cheers, JR