how to remove one-way screws?

[efffemm]

I bought a bungalow, with locks on most windows. I can't remove a window to repair it, without removing the window lock first. It has 2 one-way screws fixing it to the window frame. I can't drill into the screws, as they are a hardened metal. I tried gluing a screwdriver the the screwhead with epoxy resin, but that didn't work. I could attack the lock with an angle grinder, but I know that will make a mess, and require putting lots of protective covering in place first. Any other ideas?

[Matty F]

Does the screw head protrude from the lock, in which case maybe you can grip it with vice-grips. Or use an impact driver:

[The3rd Earl Of Derby]

One of these.

[meow2222]

Left handed drill bits work on most such things, though I dont think I've tried them on clutch head screws.

NT

[meow2222]

Left handed drill bits work on most such things, though I dont think I've tried them on clutch head screws.

might be able to dremel grind a slot into the head? I've had clutch heads out before but cant remember how.

NT

[Bob Eager]

[mrcheerful]

dremel cut a screwdriver slot, or do it UP till the head snaps off, or use a punch to start it turning, or get a cobalt drill bit and drill the head off, a tiny blob of weld gives something to turn against.

[Matty F]

The impact driver? Assuming the one-way screws are like the ones that I have, it's just a matter of turning the screw in an anticlockwise direction while holding a screwdriver firmly against it so that it doesn't ride up on the sloping part of the slot in the screw. If you can't figure out a way of clamping a screwdriver against the screw, the impact driver should work. You hit the end of the impact driver with a hammer and that is changed (via a system of springs and prawls) into a twisting motion at the screw. The hammer blow keeps the impact driver bit against the screw.

[Bob Eager]

Oh, I know how impact drivers work; I've had one for 40 years. I just don't see how that actually works in practice, but I'll try it sometime.

[mike]

"Bob Eager" wrote in news:176uZD2KcidF-pn2- [e-mail]:

I think because you apply the wist at the same time as you wallop the bit into the head.

There hasn't been much my impact driver won't shift.!

Incidentally is the impact driver the correct name - it seems also to be used for the air and electric ones?

mike

[The Wanderer]

Yes, must admit that was my thought as well, given that they are one-way screws. I would have thought the bit would just cam out no matter how hard it was hit, given the shape of the screw head

No, it's the 'Oww, Shit! bruise-the-thumb tool'! :-)

[Bob Eager]

Yes. In fact, these tools were known by that name long before the air and electric ones, AFAIK. There was an extensive discussion on the topic here, a while ago. As apart of that discussion, I produced a picture of my ancient one...it's still there...

[Blank]

There is a socket wrench type reverse driver for these screws. It looks like an S shaped slot in the socket. I received one when I bought a box of one way screws for a window guard installation. I imagine any well supplied hardware store that sells one way screws would have what you need.

"The true measure of a man is how he treats someone who can do him absolutely no good." - Samuel Johnson

[mike]

"Bob Eager" wrote in news:176uZD2KcidF-pn2- [e-mail]:

Wow - t's just like my (trying to remember) mid siixties one) which is still going strong.

But it was "made in Taiwan".....

mike

[Bob Eager]

That's mid sixties too...I bought it to undo the engine casing screws on my Honda CB72...!

Mine's a Draper - don't know where they were made at that time.

[Chris Hodges]

The "standard" way IME is to dremel a slot into them - even a pseudo-dremel or big rotary engraver is up to it (though slow) but it's worth buying a decent cutoff wheel.

[mike]

"Bob Eager" wrote in news:176uZD2KcidF-pn2- [e-mail]:

I knoooow... those poxy cross-heads :(

mike

[Bob Eager]

Changed 'em for Allen screws - I suspect most people did...!

[mike]

"Bob Eager" wrote in news: [e-mail]:

Yup - but on a Bretta 200, they _still - vibrated out of the silencer (har, har) mounts

mike

[Guy King]

The message from "Bob Eager" contains these words:

You often only got one chance to undo the sodding things, so replacing them first time was a smart move.