Tile – How to tell if the tile is ceramic or porcelain

I am going to give you a very short answer to a very involved topic. Ceramic and porcelain are basically similar products. There are very good and very cheap versions or each product. When you go to your supplier, ask about the hardness rating. Softer cheap tile usually has a redish tint on the back side and is made from softer clay, typically in Mexico. Some of the better grades come from Turkey, Italy etc. and have hardness ratings of 5 or above and have a gray or whiteish back. Most ceramic tiles have a thinner glaze finish than Porcelain. I usually prefer a porcelain glaze on a good hard base in shower and bath applications. Rather than hitting the box stores first, go to a few tile specialty tile stores where a good knowledgeable sales person can give you a good education on the differences. If and when you feel comfortable with your knowledge about tile, find a professional flooring liquidator in your area where you may save anywhere from 40 to 80% on overages, returns or closeouts. I recently purchased 600 sq feet of Turkish porcelain grade 5 commercial tiles for 60 cents a square foot that retailed for over $8 a foot, at a local flooring liquidator. (overages from a hotel job) Huge savings.

Check your Tile bit to see if you have melted the edge. normally it should feel nice and sharp against your finger. Hopefully you have a nice drill (generally battery operated may be a little on the light side).

What I do, is get a straw filled with water, or a spray bottle, and get a helper to either "pipette" or spray water onto the hole while you drill.

Second, keep the drill at slow speed - high torque, pushing hard onto the tile. You should hear it biting into the tile, As soon as you go too fast and see the tile or bit-tip going red, you have probably destroyed the bit (this is especially true for ceramic tiles)

third. as you suggested, some bits actually like it when you move the drill in an orbital fashion. I find that it cuts well on some of my bits.

So basically, if you are keeping the cut surface nice and wet (cool), and you have a sharp bit, you are doing everything right.

I have previously bought diamond bits like these with very little success. (i think you need to go for name brands here)

These are the regular tile bits which I speak of. (and I am sure the ones you describe)