Broken fastener removal

[jwmorris]

This one is my favorite IF it’s too deep to weld to AND the fastener isn’t galled in the threads. Generally used on deeply counterbored studs, common on engines these days.

Using 4130 tubing for bushings, keeps the drill straight and on center. No need for a custom arbor on this one.

After drilling the first, 1/4” hole in the broken fastener, I remove the inner tube and use a 3/8” left hand drill bit, with slow speed and decent pressure, until it grabs and backs out of the threads.

It’s better if they are closer to the same diameter if this one didn’t work I’d have gone up the next size but I do like the drill to be as large as possible so things don’t get worse (broken drill in part). You can see the chips inside the part where the bit finally grabbed on.

 

[jwmorris]

This one is a replacement of a factory insert someone messed up in an intake manifold.

I start by figuring out the best thread to continue with and thread what remains.

Then take some aluminum stock and thread the OD the same as the hole.

Then thread the ID for the factory fastener.

Now run it down in the hole to full depth and mark it for the cut.

Before I cut it, I use a bandsaw and make a slot to install it with.

Then cut it to length. This is it next to the factory thread insert.

Then reinstall.