Drilling granite pavers

[inox88]

Hi I have some 12mm holes to drill in granite paving slabs to fix stainless steel balustrades to patio area, i'm wondering will sds bit with hammer drill do the job or could the hammer action cause the slab to crack the slabs are 30mm thick, my plan is to drill through the slab down into the block below and chemical anchor in a threaded stud to attach the post to

 

[theknobs]

Hammer or SDS will be very likely to crack the granite. You would need to use a sharp bit, preferably diamond, and keep it cooled with a stream of water while drilling as the heat from drilling could also crack the slab. It's best if you can find a spare bit of granite to practise on first. It will be a slow job.

 

[piglet11]

Definitely not SDS.

Get a diamond core bit and snap off the core with a strong screwdriver as you go along.

 

[Smurof Yid]

All good advice, I'd also add that when you want a nice clean 12mm hole, you don't need to start with a 12mm bit. Drill a small hole, (3mm), then 6, then 9 finally 12. It takes a little more time, but not as much as you think, because a 12 mm hole is a bitch to push. And Brutal heat on your bit. I'd rather buy a new 3mm bit, than a new 12 mm bit. Feel me? Sneak up on it.