"Gerry" wrote in message
ps.com...
On Nov 3, 1:48 pm, wrote:
I have a metal pin look like this

| \
=====\
| /

It is attached to glass panel

| glass
|====\ glass
| glass

I need to take the pin out. The flat part of the pin has
dimension of 5/16 inch. The pin attached to a glass panel. I bought a
1/8" titanium bit and drilled the pin hopefully to break it apart.
The drill bit just made a scratch on the pin but does not penetrate.

How should I take it out without breaking the glass panel ?

Thanks,
Nick

I'd try nitric acid


Acid would be good, but nitric isn't all that good of a choice.
Hydrochloric will dissolve steel readily, and is inexpensive and readily
available, unlike nitric. Sulfuric would do the job, too. Be sure to
keep it submerged adequately, not only for cooling, but for keeping a fresh
supply of acid at the work. Give the acid plenty of time to get the job
done. HCl will actually work quite fast, thus the concern about heating.

Wear eye, skin and lung protection when working with these acids------and
remember that the gas coming off will be hydrogen-----so do this where there
is adequate ventilation, and there's nothing that will be ruined by rusting.
If you do this operation inside, where there are iron surfaces, you can
expect all of them to be damaged by the fumes.

Harold