I broke a tap off in a blind hole and it is even with the surface. The tap broke when I was trying to back it out. Anyone have any great ideas how to get it out?

Take it to a shop with a edm machine if potarable. Are thay do have tap extractors for four fuuted taps.

What kind of metal is it in (aluminum, cast iron, steel)?

I've never had any luck with tap extractors myself. Usually just end up with bent extractor tangs. What part is it in? If no edm is available, a carbide endmill works great, but that needs to be done in a milling machine to hold the part and tool solid, or a drill press if you can feed the bit slowly. What size tap? I have used a pencil grinder (dremel will work too) and plunge the grinding wheel down the center many times. Did it break from bottoming the tap out in the hole?

Thanks for the reply guys. It is in an aluminum exhaust manifold.

I was cleaning the threads up and got to the bottom of the hole and then tried to back it out. It was stuck and a little bit more pressure is all she wrote.

I have used reverse drill bits before. Try to use a dremil to make a flat surface on the tap, in order to get a straight shot. The last time I did this was actually on an aluminum exhaust manifold for a jet ski. Took awhile but works. It will usually drill for a bit, then grab the tap and out she comes.



Darrell.

Apply penatrating oil. Use a center punch at the appropriate angle to strike and start the tap out. Use an electric engraver to vibrate it the rest of the way out. If this doesn't work, the safe route is the machine shop.

I use a mig welder and get bolts and taps out all the time. It may take several tries but I have never failed.

Aluminum is a gummy metal and there are tapping fluids that are intended for use in aluminum. Not expensive and worth having for future projects. If I am recalling correctly I believe you want to use a 2 flute tap for aluminum. Good luck removing the broken tap! A good machine shop may be the best bet as taps are hardened steel and you will have a difficult ime drilling one out in the soft aluminum.