Made my own ox nose tile paying the cost of a low speed grinder and this round nose cutter. You'll need to press down on your work, use flat-surfaced plywood under the tile you want to round for the roller to slide over, and hold the tile between 1/64th and 3/16th from the edge. This way you get a completely different look of a bullnose. Wear a raincoat and keep the bit dry, turn on the water until it drips out of the bit, use the lowest speed you can, and keep the side sander straight as you work. There was a side grinder that I bought with the racquet. It eats away at your wallet, but when you see how much 90' Bullnose costs, the tool pays for itself the first time. Walk slowly and don't stop at the ends, but continue the same movement. I used tile trimmings from both ends of the ones I sanded to prevent rounding of the ends of the tile you're working on. It takes practice and a stable buck.