My Unibits last a long time by buying a couple of 1/4" metal drill bits. I make a pilot with a 1/4" drill bit and then drill with the unibit. I also use a small drill bit when trying to make bigger holes in metal with bigger drill bits. This saves the point. By the time they go bad, I usually just toss them. They are very expensive but I got the most out of them by using my method. I dont have any suggestions for sharpening.
