removing security screws

[flashbang]

This may not be of much help to you, but...... I had some old and rusty screws that I needed to be removed from a wooden gate. I heated the screws with a soldering iron (admittedly only 6 gauge) and found that they removed very easily. My first attempts to shift them failed because they just sheared.
Thought I'd mention it because if you could heat the screws a bit it would take a lot less torque/grip to undo them. Might be a problem if they are contacting cast iron though, as that would make a very good heat sink.
Good luck.
Flashbang.

 

[amandaeb]

Thank you to those who replied since I last looked.

Still haven't tried removing them, other jobs seem more urgent at the mo! (Clearing up small jobs to get materials and tools out of the way before the electrician comes to do a couple of days work.)

But i will consider everything all of you have said.

Amanda

 

[amandaeb]

I thought I'd provide an update on the screws, in case anyone searches this forum in the future for the same problem and to say thank you for all your ideas.

I tried drilling a pilot hole in the screw head with, admittedly a cheap, HSS bit. This was slow work, but I did get an indentation in the head of the screw. I then tried the drill in reverse to see if it would bite in and turn the screw, but unfortunately it didn't. I then tried the screw extractors, but they didn't get anywhere, admittedly these were from the £1 shop!

I then tried the idea given of creating a slot across the head of the screw. I don't have a suitable power tool, but I tried a metal hacksaw and that worked really well. Luckily the screws were proud of the surface, (they were too big to countersink into the provided hole.) After a couple of minutes of sawing I was able to use a large flat head screwdriver to carefully turn them, and got them out!

I'm really pleased, so thank you again for all your ideas.

Amanda

 

[AdamW]

Proof that security screws are really effective!

 

[Porker]

Mandate - your assumptions are correct. I was flicking through an Axminster tool catalogue and they show something that looks exactly the same. They have a knackered posi screw and the tip of these things has very fine anti clockwise thread which bites into the remains of the screw head with a reversed cordless drill. Looked like a size 8 screw at a guess in the pics.