The usual method is to use an easy-out -- very coarse left-hand thread,
available from many places. You have to drill a hole down the center of the
broken screw, however.
You can also make a tube to fit over the broken screw, cut teeth in the end,
and make a hole around the screw as deep as necessary. You then put a wood
plug in the new, larger hole.
If the break is near the surface, you can use a thin cutting disc to cut a
screwdriver slot. This will leave you with small cuts on either side of the
hole.
Finally, you can just leave it, put in a plug, and start over nearby. If
you're taking things apart, take out all the screws but the broken one and
use a flat bar to gently pry it apart.
What we really need is an acid that will dissolve the screw but not the
wood -- which is how you remove a broken steel tap from aluminum. Ideas,
anyone?
--
Jim Woodward
www.mvFintry.com
..
"Keith" wrote in message
...
Does anyone know of a source for these?
I occasinally snap the head off a screw and need something to back them
out
of the wood without carving a huge hole out for pliers. I would imagine
what
I need is something that's kind of a mirror image of the Craftsmen screw
removers... I need something with a concave cutting "dimple" that would
fit
over the end of a screw shaft and bite into it, allowing me to back it
out.