First, let me clarify that I'm not using them as advertised. First, I drill a hole the size of the faucet with a cobalt drill bit. I do this to ensure the durability of these bits. Then I thread the hole with these bits. I have an expensive set of tungsten steel taps that don't last as long as these taps when drilling holes first. If these taps come completely out of the metal piece, do not reverse the drill motor and try to remove the tap. You will break the faucet. I learned it the hard wayβ¦