
I bought these drill bits for a hardwood ship building project. They fit perfectly into the wood. The variety of sizes and the free packaging of the drills were just what I needed. I sharpen them with a variable speed motorized Dremell tool. For what they are worth I have no doubt I will get my money's worth. I haven't used them in metal, but I'll probably drill aluminum with them at some point. Based on their hardwood performance I don't think I will have any problems. I can't tell how they will perform in mild steel but with the right drill speed and lubrication I think they will.