How to remove anti tamper screws

[Martino]

Hi folks,
I've got some security grilles attached to some of my windows. They're attached on the inside with some screws into the masonry. These screws have tamper proof heads - i.e. can be turned on way (to tighten up) but not the other - so I can't undo them. To make it worse they are quite well hidden by some of the metal work of the security grill so I can't get at them with grips or anything.
I need to remove the grilles so need to find a way to remove the screws.
Is there any kind of ant-anti-tamper tool out there designed to remove these kind of screws easily? Or am I going to have to resort to brute force and ignorance and a lot of making good afterwrds?
Any suggestions/pointers gratefully received.
Thanks.
Martino

 

[Stivino]

You might have to grind the heads of them and leave them in place.

 

[wotan]

Cut a slot in the head, with a dremmel fitted with an abrasive disc.

 

[ColJack]

try the JML screw extractor set.. supposed to be for rounded or cammed out screw heads, but should work on these "one way" screws..

 

[joe-90]

If you can't reach them with a grinder and you have an arc welder you can melt the screws and pull the grill off. I know it sounds daft but it does work.

 

[Hobbyist1943]

try the JML screw extractor set.. supposed to be for rounded or cammed out screw heads, but should work on these "one way" screws..

I bought a new set of these off eBay for a fiver, also with the intention of extracting some security screws. However, I'm sorry to say they didn't worked for me

Although I rotated them slowly and applied as much pressure as I could, they merely began to drill into the screw heads in an anti-clockwise direction and are now lying in a drawer.

 

[ColJack]

they should eventually bite and turn the screw out.. if not then at least they will drill the head off so the OP can get teh grille off.. then he might be able to get a hold of them with a pair of mole grips..

 

[^woody^]

Toolstation £3.28 for the set

 

[Hobbyist1943]

Those bits from Toolstation look very different to the JML set which have tips very similar to drill bits.

 

[Thermo]

i used those ones. they took two out, but just ground the heads out of the rest!