I had to drill 35 holes 10" through the tile to install a lower removable track for an accordion hurricane blind in Florida. Excellent for this money. Bought 10 because I didn't think I had enough, only used 4. Not so bad! But you have to use them low, slow and wet. and they work great. The tile I was dealing with was textured, with faux grout lines. I used plumbing mortar to make a ring around my mark like a dam. work) wide enough to kneel on either end and hold it still while I drilled. Once the mount is centered, fill the hole with bottled water and don't rush! Start very slowly and don't press down hard until the ring is through (frosting) on top. Then you're spot on, just drive at VERY low speed.