No retaining screw on euro cylinder lock...?

[Roger B]

Hi, looking for some advice, if possible...

I am looking to replace my rear door euro cylinder for an anti snap one, but can't see a retaining screw. I have replaced my porch door and garage door euro cylinders, but can't seem to figure this one out...

Where the screw should be there is some kind of metal 'hole'. At first I thought it was an Allen key socket, but none fit (it appears to be perfectly round). Please see pictures.

The door has a multi point looking system which I have attempted to remove too to see if the screw was under the metal facia, but I couldn't see anything...

Any ideas....?

 

[crank39]

It will be a long grub screw with an allen head, easy way to check this is look at the hole while lifting the handle up, if the slider behind the metal slides up and covers the hole then its a grub screw for certain, putting a standard machine screw in with a pozi head will obstruct the sliding operation of the locking mechanism and jam it up, using a grub screw means you can send the grub screw deeper beyond the slider so it won't obstruct, if your allen head is rounded then it will need drilling out or hammering a thin flat screwdriver in to grip it and undo

 

[Roger B]

Yep, that's exactly right - I noticed the mechanism was going over the hole when using the handle, so figured that would be reason. Thought it might be some obscure locksmith fixing though...!

Yeah, the Allen key socket looks rounded to me. Joy of joys

Thanks for the reply, very much appreciated

 

[crank39]

Drilling isn't as hard as it sounds, I've lost count how many I've drilled in 30yrs of being a service engineer

 

[Roger B]

How would you go about it, if you don't mind?

I've a set of these...

Bolt Extractor Set 5 Pieces - Screwfix

Order online at Screwfix.com. Carbon steel construction. To remove broken bolts, drill pilot hole in broken fixing and screw in the LH-threaded extractor. FREE next day delivery available, free collection in 1 minute.

www.screwfix.com

... but can't say I've ever had that much joy with them...

 

[conny]

How would you go about it, if you don't mind?

I've a set of these...

Bolt Extractor Set 5 Pieces - Screwfix

Order online at Screwfix.com. Carbon steel construction. To remove broken bolts, drill pilot hole in broken fixing and screw in the LH-threaded extractor. FREE next day delivery available, free collection in 1 minute.

www.screwfix.com

... but can't say I've ever had that much joy with them...

I've never had any joy with those things either.
Are you sure it's not the end of your allen key which is rounded? If so, then a new Allen key might solve the problem.
In the past I have managed to free a grib screw by hammering a similar sized torx driver into the grub screw with an appropriate holder. Mind you, they have not been recessed into a hole, just flush with the surface. You can also buy a left-handed drill bit which may free it when you put the drill in reverse, but make sure the chuck is really tight and start slow with light pressure.

 

[Roger B]

Yeah, definitely rounded. I have a few Allen key sets and none are getting any purchase.

I was lookong at left handed drill bits, so will grab some of those.

Thanks for the advice