Broken tap removal - pure genius

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Wish I'd thought of that back when I was working.  The boss would always bitch at anyone who broke a tap in a workpiece. Usually had to drill em out with a 2 flute carbide drill........ then hope for the best!

 
They have been making tap extractors for years. They had them when I started in tool & die in the 1960's but usually do not work. If tap stuck enough to break tap they usually do not come out with the extractor. His was home made the factory made have spring steel pins. We usually put in EDM and burned them out Russia invented the EDM in the 1920's way before the U.S. had a clue. The U.S. could not figure out how Russia was putting such small dia. holes in rocket engine parts because all the drills we had that small would not drill the exotic materials. They were actually burning the holes with EDM and figured out they could run through a spiral guide and do a curved hole which made their rocket engines much more powerful.
Good tap extractor they should still be available. I hate 4 flute taps also I use 2 flute plug only.

 
Yep.......they still make finger tap extractors. The taps today from over seas are way to hard. They snap a lot easier than the German or USA made taps. As David said the 4 flute break easily. If a flute is eliminated then you have more back bone to the flutes that are there.  I guess, in a pinch, the home made one is worth a try but........ it will twist and bind further lessening the chance for extraction.  

A bit more on the EDM machines (electronic dismissal machine). I ran these a whole lot as a tool and die maker. Mostly burning intricate precise figures through Extrusion dies .  I was warned about the potency of the machine by the current journey man die makers I worked with. The original machine turned out to be deadly. Some how the EDM head was not grounded properly. The operator ( I was told the inventor)  leaned forward to get a good look at the part being burned and touched his forehead against the EDM head. The current went through his brain and cooked him instantly.  

 
The shop I was engineering manager at in China had over 50 wire EDM machines. Never seen shops in U.S. with near that many and we were considered small in China.
I went to Cincinnati Milicron school back in the 70's for their conventional EDM. They had built a huge one for Ford that could burn a hood draw die. I think the 4 guide columns were 10" dia. and it shook the building if you turned it up, lol. I went into engineering before lots of CNC.
There is one sitting in my friends restoration shop. I have been thinking about building a mold for the emergency brake light and trim ring.

 
Many times, over the course of the years, we all have had a tap break on us at the shop. If there is any small bit sticking out of the hole, one of the guys has gotten to be a pro at pinpoint welding a nut to the end of the tap, through the hole in the nut. The tap can then be unscrewed with a wrench on the nut. So far, we've had 100% success at removal this way. I am, however, aquainted with using tap extractors as well, which have served me well. 

 
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