I was doing the same kind of thing but into granite, I had bought a second hand SDS drill to do so, although turns out the hammer function was not working properly so didn't get anywhere, borrowed a mates and it flew in, had to drill 4 x 16mm holes and 4 x 10mm holes, impact energy is where it's at as @chiroshi is saying
I was doing the same kind of thing but into granite, I had bought a second hand SDS drill to do so, although turns out the hammer function was not working properly so didn't get anywhere, borrowed a mates and it flew in, had to drill 4 x 16mm holes and 4 x 10mm holes, impact energy is where it's at as @chiroshi is saying