I make jewelry. I bought them to drill small holes in soft metals like silver and copper. I use Rio Grande's Burlife lube and still I can't drill more than 1 or 2 holes in 20 gauge soft metal before the drill bit becomes so dull it's almost impossible to drill it. I bought this and a larger set from the same manufacturer. Both drills have the same problem. A shame. I think cheap drills are really cheap. Good point: They fit a multi-chuck Dremel flex shaft.