Probably ideal for plastic or very soft metal like brass but not steel or aluminium. With my drill press, a vise, and some oil, the drill bit easily cut through the side of the nut. The faucet was another problem. At first it came in normally but with some oil it twisted twice, loosened once I had about 3-4 turns but the tap is too thin and brittle and will break with the slightest sideways movement. Luckily the drill managed to drill at least part of the tap out of the nut.