Cutting a perfect 120mm hole in 22mm ind/s-stone

[Left handed]

Part of my finished patio will (unfortunately) need to have a washing line in it.

So I would like to cut a perfect 120mm hole in 22mm indian sandstone.

Been looking online and think a diamond core drill bit could be my best option. Over £30 for one bit so would want to get it right. I've got a SDS drill already.

Has anyone done this before? Was it successfull or is there a better alternative?

Thanks

[digerjones]

That's a big hole for a washing line, project I'm on at the moment needs a washing line pole hole. I'll probably do it on a joint and cave 2semi circles with grinder

[Left handed]

The washing line is held in place by a "ground screw", this let's you take washing line in and out if you want. So hole needs to be big enough for it too.

Thanks

[jwill]

Sds isn't usually upto core holes. You got something with a clutch?

[Left handed]

I've only got my SDS drill and cordless drill.

Plan B??????

Thanks

[lutonlagerlout]

makita core drill is what we use for coring holes
coring indian stone is a real heartbreaker
better to mark your circle and drill a load of 7-8mm holes with a diamond drill bit
LLL

[Tony McC]

Does this 'ground screw' come out each time you take down the washing line? If so, I can see that getting weaker and weaker with each use.

I have a rotary washing line which slots into a concreted-in, permanent socket beneath the paving. I core-drilled a 60mm dia hole through Kota Yellow limestone to accommodate the 55mm dia pole which carries the line rooughly 2m above GL.

I used a professional quality core bit from back in the days when I had a civil engineering business, drilling a 8mm pilot hole first as a guide to centring. It fairly slipped through the stone, as though it were butter.

For a 120mm dia hole, we'd normally use a jig to hold the drill steady and perfectly vertical above the stone. It's a bit too big to rely on holding it steady by hand alone.

If you have a local monumental mason, they might be able to drill it for you, if you cross their palm with beer vouchers.

[Left handed]

I've managed to cut a perfect circle in the indian sandstone and after a bit if trial and error and once i'd refined my method on off cuts it was remarkably easy.

I've been in touch with tony m and he has photos and description so hopefully he will upload it. I've been given a lot of help from you guys so hopefully I can return the favour(s).