A diamond core drill bit is imperative when you need to drill holes in tile for any reason because it can make the process easier and the results flawless.
To have the best results with a diamond core drill bit, use it at slow speeds. The larger the diameter of the hole you are drilling, the more slowly you should drill. For example, a 6 mm core bit should be used at 2000 RPM, while a 24 mm bit should be used at 700 rpm.
Use Bits in Water
Unless you have purchased a drill bit that specifically states it is manufactured for dry use, any diamond core drill bit needs to be used in water, and underwater is best.
This enables the bit to stay cool, water to circulate and remove debris, and keep the cutting area lubricated.
A hint for making this process work is to use blue tack or plumber's putty, attach an old plastic bowl filled with water to the tile, and then drill through the bowl and through the tile.
If you use the proper techniques for cutting tile with diamond core drill bits, you will have a successful experience in creating holes in tile and the holes will look expertly cut.