In article ,
Dave wrote:
Dave Plowman (News) wrote:
I've got a couple of very small self tappers which have broken off flush
with a blind housing made of thin mild steel - car bodywork. Due to being
rusted in place. What's the best way to remove them with minimum damage to
the bodywork?

To do this, you will need two things.
An extreamly hard drill and some means of stopping the twist drill from
going off the centre of the self tapper and through the softer metal
around it.

The twist drill could have to be a solid tungsten carbide one (or
possibly a C 1150 or D 200, but I have hit a brick wall in finding a
source of them. They are considerably harder than a cobalt drill.) and
the only way you can prevent it taking the easy way through the softer
body metal is to use a hardened bush that can be clamped onto the body
metal, to guide it through the screw. Unless you are very adept at
making the drill stay on course.

I do have tungsten carbide drills I use for drilling PCBs. But not sure
I'd risk them on this - even if I could rig things up to use the PCB drill
press.

An alternative, but maybe expensive way, would be to find someone who
can electrically erode it, by spark erosion.

Good luck. If it was a local job, I would get out my hard drills and do
it for you.

Thanks for the offer. ;-)

Dave

--
*Strip mining prevents forest fires.

Dave Plowman London SW
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