In article ,
RJH wrote:
5 of 8 allen bolts fixing 2 metal sheets on my car have stripped the hex
key. They are/were 4mm, and I think stainless steel. I've tried drilling
one out to 5 and 5.5, but the spirally tool in this pic:

https://www.icloud.com/sharedalbum/#B0zGFssfGG2m5Jn

can't generate enough purchase. It grips a little, but slips. I don't
know what that other bit is in the photo - memory suggests it's a screw
extraction tool I got from Aldi. There isn't enough head on the bolt to
use mole grips.

I'm not sure if I'm using the extractor incorrectly, or it's just not
very effective. Thinking now about cutting a slot in the head and trying
a flat blade screwdriver. I don't think they're outrageously tight. I
can access the other side - but I don't want to damage the thread in the
sheet the bolt screws into.

Suggestions appreciated.

A suitable sized Torx bit hammered in often works.

--
*A fool and his money can throw one hell of a party.

Dave Plowman London SW
To e-mail, change noise into sound.