I bought this to install a reverse osmosis faucet that required drilling into a granite countertop. It's a little hard to start with hope. Hold the drill firmly or even use a jig. It's also a good idea to put masking tape on the area you're going to be drilling so you don't scratch the countertop if you slip and it's easy to slip before the hole moves. Just let the tool do its thing. Work and keep some water on the tip of the drill. Put something under the drill site to catch sand and water.