I have used them for drilling wood and metal. They are much better than the so-called "titanium" drill bits, which are pure junk. Tip: When drilling in metal, dip the tip in used (or new) engine oil and set the drill to "slow" speed. Settings and GO SLOW. Take your time and re-dip the end of the bit in the engine oil every few minutes. If you do it this way, you will never wear out the bridle - it will last you for years. Of course, don't sideload it and don't put undue pressure on the drill bit while drilling. So if you're using heavy engine oil (or cutting fluid), work SLOW and avoid sideloading these drills for years to come. Make sure you write your name on it, and if you're smart, don't rent your beats unless you really know who you're renting them to, because most people have no idea how to take care of them must.