>Think I missed the original post ... I have never, ever, had any luck
using
>the tapered extractors.
Once or twice, but pretty-much never. I have removed some pipes this way.
>My best luck so far has been with drilling in stages to the minor diameter
>of the threads, then picking out the remaining pieces with a dental pick.
The trick is to use LEFT-HANDED drills to do the drilling. A standard
right-handed twist drill will tighten the broken bolt into the hole. The
left-handed drill (obviously, you need a reversible drill-motor!) will
impart a torque to the bolt which tends to loosen the bolt instead.
Generally, I have found that the bolt will come out as a result of the
torque and vibration before I am done drilling.
If I have drilled holes with a left-handed drill and the bolt is still
there, it's unlikely that an easy-out will work.
Sears is selling some kind of combination left-handed gizmo to put in your
reversible drill-motor and use to remove broken bolts. I have no idea if
it works, but they sure are more expensive than buying left-handed drills.
>If that doesn't work, there's always Helicoils ...
Been there, done that, too.
>One of these days I've just got to build an EDM.
Yeah, those broken easy-outs are HARD!
Phil Ethier
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