I was drilling stainless steel, only had to drill two holes, fairly thin steel. The pilot drill broke off at the base halfway through the first hole. I started well enough to finish this hole but the shaft got stuck in the base and I couldn't get it out. The carbide tips are monsters, they chew through stainless steel like cheese, but the rest is mostly cast iron. Too bad, with a slightly better base it could have been a really good beat.