Ever seen this?

[Tomme boy]

First I have seen this. Not ideal but if it works right?

 

[Brad]

This Old Tony is a good site. He does some good editing and has a good sense of humor too.

I saw that video and was impressed with the idea. Like you said might not be ideal but if the setup is right it will work. Getting the cutting edge on center would be the hardest part. That and getting it aligned rotationally to cut properly,

 

[JustJim]

I've sectioned a tap, brazed the threadcutter on a tool shank, and used that to cut threads on a wood lathe. Definitely not the same thing though.

 

[Ian]

I've taken a broken tap, ground the tip square, ground all but the last tooth off of one side, and threaded the end of a tube with it single-point style, but again not quite the same thing.

 

[Tomme boy]

I try to save all of my broken taps to make a bottoming tap.

Sometimes that extra 2.5 threads can help. Just don't bottom the bolt out.

 

[Petrol & Powder]

This Old Tony is worth watching just for the humor alone, but if you're not careful, you might accidentally learn something too.

 

[smokeywolf]

Interesting. Think probably you'd be somewhat limited by the material being threaded. Rigidity might become an issue.

I have a couple of 5" to 6" long pieces of 3/8" and 1/2" diameter drill rod, which I cross drilled near each end for the dia. of tap shanks. A set screw in each end secures the tap shank (reground broken tap). The broken tap mounted cross-ways can be ground for boring or single pointing.