Do they hammer straight into a stone wall or do pilot holes need to be drilled first? I just want to relocate a light switch (along with the wires that feed to it) a few meters to one side.

Thanks.

just hammered in. Will depend on your the wall though.

Why not fit conduit with a couple of clips drilled in place?

That's a good idea. I'm doing it for a neighbor and don't expect to be paid (even for materials) so it's on the cheap, but a short piece of conduit certainly won't break the bank.

Try a 'bendy' clip first. Watch your fingers

Try a 'bendy' clip first. Watch your fingers

Been there done that. I use a pair of needle nose pliers now to hold it in place while hammering.

if it is actually stone i doubt you will penetrate that even with hardened pins if on the other hand if any other material //block /brick etc you should get lucky with as suggested a pair of pliers to hold position and a well aimed first sharp hammer blow should do the trick

or also suggested conduit / clips /plugs and screws

^ Thanks for the echo Gerrymandering

And don't tap gently when driving the nail/pin in...give it hard, straight-on hits with the hammer. Trying to hammer the nail/pin in gently just greatly increases the chances of the concrete shattering out. And most definitely using some needle nose pliers to get it started is a good idea...it's what I do. The builder of my house definite used "hard" concrete.

I use wire channels with the pop off covers. My whole house is wired using them. Easy to install and make any changes at a later date and can be painted to match the walls. I don't rely on the sticky tape to hold them in place and drill holes in the concrete and mount them using anchors and screws.

Other than using needle nose pilers for the clips is to insert the nail first and then bend over the long end to hold the nail in place and use the long end as a handle to hold the nail. Having said that I still use pliers to hold the nail.

I picked up a small bag of bendy clips and was given, in a separate bag, some of the shortest nails I have ever seen. They are only 6 mm long, and the needle nose pliers took up half of that. I don't understand how such a short nail is going to have any holding strength.

Didn't have much luck with the first few - the surface concrete just crumbled. Finally on the 4th try I got one to go in cleanly. I should probably get a heavier hammer, as I had only a lightweight carpenter's hammer available.

I think the wire channel is a good idea since I need just a short run. Hope my village hardware shop has it.

You do need a heavier hammer for best results...and also get one where the hammering head is as flat as possible. The more rounded/cursed the head is the more chance of hitting the nail/pin at a "slight" angle which greatly increases the concrete to crumble. If you taking say six hits to drive the nail in that is too many....you are probably going to end up in failure...you should be getting the nail in in approx 3 or 4 good hits. And yeap, the needle nose pliers will take up a good portion of the short nail's length, but it greatly increases the first hit or two being successful.

^ looks like plan B then