"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.

The name you need to use if you have to buy a replacement is a hexagonal
socket screw. If, as I suspect, there is no head on the screw, it is a
hexagonal socket grub screw.

....
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?

That would be my approach, if you can get to the screw with the hacksaw and
it is large enough that the slot width is not more than 1/3 the screw
diameter. However, I wouldn't try reusing a screw that had been removed that
way. You will need to buy a replacement, either from the manufacturer or a
good hardware shop.

Colin Bignell