Broken tap removal
Posted: Sat Aug 19, 2006 11:39 pm
I just finished removing a broken tap from the Cub's radiator casting. Although at first I didn't know it, the broken off stud turned out to be a broken off tap. (No I didn't do it!) I tried to drill it first. The special drill bit that I bought wasn't special enough. I jigged it onto my metal lathe and used a HSS end mill. It wasn't "Special" either.
I finally ended up using a Dremel tool and a bit with an cylindrical abrasive end on it about 1/8" dia. x 3/16" long. I didn't think it would do the job - just break up or not cut at all or load up and quit cutting. I used it just like an end mill. I kept blowing the hole clean with compressed air. It took a WHILE and 2 bits, but I cut through the tap and picked out the pieces (of course, the hole was off center by now and not circular). I then drilled the hole true with a tap drill and tapped it for an oversize threaded plug which was then cut flush with the surface.
Finally, I center punched the plug where I wanted and drilled and tapped for 1/4 - 20 thread since the other holes were that size. Just as easy as pie! Don't sell that dinky Dremel setup short.
Hope this helps someone.
Rich
I finally ended up using a Dremel tool and a bit with an cylindrical abrasive end on it about 1/8" dia. x 3/16" long. I didn't think it would do the job - just break up or not cut at all or load up and quit cutting. I used it just like an end mill. I kept blowing the hole clean with compressed air. It took a WHILE and 2 bits, but I cut through the tap and picked out the pieces (of course, the hole was off center by now and not circular). I then drilled the hole true with a tap drill and tapped it for an oversize threaded plug which was then cut flush with the surface.
Finally, I center punched the plug where I wanted and drilled and tapped for 1/4 - 20 thread since the other holes were that size. Just as easy as pie! Don't sell that dinky Dremel setup short.
Hope this helps someone.
Rich