"Dan Gravell" wrote in message
...
Hi there,

I have a very small allen key screw which screws into the bottom of my
shower mixer unit to fasten the thermostat and control to the shower.

I recently had some problems with the shower running colder than normal
so following the advice of the manual (and this newsgroup) I took out
the thermostat, flushed it and gave it a good clean, and reinserted it.
Unfortunately this didn't work, and after a phone call to the
manufacturers I got sent a new unit (can't fault the service btw, the
company was Marflow).

Now, the problem is that when I went to install the thermostat, I
realised the screw's inside has become threaded, in that it is almost
circular and not hexagonal any more. The allen key (which I suspect was
probably slightly too small in the first place) just rotates in the
socket. This "threading" happened when I rescrewed after trying the flush.

I tried extracting with all manner of pliers, assuming I could get a
decent grip and twist it out, but to no avail. Perhaps I screwed it in
incorrectly.

Anybody got any suggestions for extracting this screw? I thought
possibly using a junior hacksaw to create a slot to use a normal
screwdriver to screw it out. Would that work? Or would it just mangle
the screw?

Thanks, Dan

p.s. Sorry if threaded is not the proper term... Perhaps someone could
suggest a better one to help other people searching for similar problems.

I may have misunderstood the question but no-one has mentioned what I call a
stud extractor but should, I suppose, more correctly be called a 'broken
stud extractor.' They are intended for use on a broken stud (When a
hexagonal bolt head has broken off or badly damaged. A pilot hole is drilled
into the stud and the extractor pushed into the hole and the extractor used
to extract the stud. With luck the rounded hexagonal hole may be sufficient
to engage with the extractor and you will not to drill a pilot hole.

For a picture do a Google on "broken stud extractor" A quick look shows that
Axminster sell a set at £1.95 and Machine Mart for considerably more!

Have you any friends or neighbours who have done their own car maintenance?
They will almost certainly have a set.

Ask you local garage.

Look in Yellow Pages under 'Tools'