I am currently tiling my bathroom and have bought lovely big porcelain tiles. The only problem is that I cant cut through them. I have an electric tile cutter which is great for straight lines but no drill bit will even touch them. Even a diamond drill bit. Any ideas?
While looking for a picture of the appropriate drill bit, I found this U.K. site: http://www.leafcutterdesign.co.uk/armeg-drill- p-383.html
As you can see, it's as much about the shape of the bit as it is about the hardness. They are expensive though...
It's important with a diamond bit to keep lubricating it continuously as you drill. Drill at a moderate speed, and just use water and a spray bottle, (but don't get water on the electric drill)!
The hard bit is the glaze. Once you get through that it is easy. Try tapping it lightly with a hammer and pin punch just to break the glaze and you will be able to drill it OK.