This is the most useful drill bit I have ever bought. I often need to drill clean holes in relatively thin metal and plastic, and traditional twist drills are terrible for that (the holes always come out triangular). On the other hand, this drill makes clean and perfectly round holes in plastic, aluminum and steel. I've had it for about nine months now and use it several times a week, mostly on plastic and aluminum. It's still as sharp and effective as the day I got it, despite the occasional hole in the steel. Use some coolant (e.g. Tap Magic) and it should last a long time.