Usually all home owners in some point or the other will like to have a towel stand or a special mirror place in the bathroom and that will involve drilling some kind of a hole into the ceramic tiles. Ceramic tiles are a different ball game when it comes to drilling as they are hard and when applied with extra force and can break.
The composition of ceramic tiles used in most homes is that they have a soft inner core and then thin layer of hard glaze which means that once you drilled a hole into the outer layer the rest of the drilling will just be a breeze. The ceramic tiles can vary in hardness across countries or even regions and that hardness is purely based on the clay and the silica content in the tile. Also, the hardness can vary depending on how much time the ceramic tile was baked in the kiln.
Most of the ceramic tile available in the market today can be drilled into by using the carbide drill bit. These bits generate a lot of heat and hence you need to make sure that you have adequate oil or water to cool the bit otherwise it can be permanently damaged. The diamond drill bit is another solution but they are expensive though they work beautifully for drilling holes into glass or ceramic tiles. The soft tiles can be drilled with carbide drill bits but harder ones will surely need diamond drill bits.
As far as the drill goes never ever have a hammer drill to drill through ceramic tiles. It causes enough vibrations that it will be crack the tile. You will have to use the other type of drills available and also make sure that you drill through the hard glazed covering of the tile very very slowly and by that I mean using absolutely the slowest drill speeds.
The ceramic tile drilling is a very slow process initially as if you get it wrong you will have either the cracked ceramic tile or scratch marks on the tile. The scratch marks can happen if you apply more than the needed pressure the drill may slip away and scratch the surface of the tile.
Be careful and approach slowly and your work will be done without any damage to the tile.It is for your benefit that you tread cautiously when you are doing ceramic tile drilling so as to prolong the life of the drill bit