BillM wrote:
"komobu" wrote in message
...

Also, please comment on grabit and other extracting
methods. What do
you think is the easiest way to remove a broken bolt?

Thanks for any advice
Pat


My favorite method is to center up an oversize hex nut (3/8
nut on a 1/4 bolt etc.) over
the broken remains, use a mig welder to weld the nut to the
broken stud/bolt.
Give it a shot of Kroil and unscrew. For small stuff drill
a hole in some sheet metal,
weld it to the screw, and weld a hex nut to the sheet metal.
Lots of Kroil, maybe run
it through a couple of heat/cool cycles, be patient. Works
90% + of the time.

Bill


Komobu said:

"I had intended to say in the initial post that welding wasnt an option
for me...I want to learn how to weld..."

*If* you have access to an oxy-acetylene torch with a cutting head, but
do not know how to weld, here is another handy-andy "hot wrench" trick.
It won't work in every situation, it can be quite messy, and gooey gobs
of red-hot sparks may fly in every direction. But sometimes it really
works well and may be the only way and/or last resort. In general, the
larger the diameter of the broken bolt, the better this works -- and not
just for broken bolts, but for broken or seized fasteners of all kinds.

Using a cutting torch head, adjust the oxygen and acetylene pressures as
you would to cut a piece of flat steel of roughly the same thickness, or
less, as the broken bolt's diameter. Heat the exposed area of the broken
bolt as rapidly as possible. Speed is of the essence here, or you may
end up welding the broken bolt to the surrounding material (which I have
done, thank you). The thing to keep in mind is to prevent the broken
bolt's surrounding material from approaching welding temperature. Once
this surrounding material begins to glow, it is time to remove the
torch, pause, and allow everything to cool down. Then, resume.

When the broken bolt end is red-hot, blast away with the oxygen. This
will vaporize the molten metal -- look out for red-hot molten metal
blowback upon your person. Repeat as needed until all of the broken bolt
has been vaporized. If the bolt was in a blind hole, you will have some
slag to clean out. If the bolt hole goes through, you can chase out the
larger bits of broken bolt by getting them red-hot also, and blasting
away with the cutting torch head's oxygen. In either case, *remember to
not allow the surrounding material to attain welding temperature*.
Finally, run a tap in and out and the bolt hole should be as good as
new. Well, almost as good as new...