Based on my experience with these industrial drill bits I would not recommend them to anyone. While they may be affordable, they consistently fail to drill through the toughest materials .The packaging claims that they are made for heavy-duty tasks, but they do not live up to that promise. Although the design seems promising, the quality of the bits is simply not up to par. Industrial and Scientific buyers beware: these bits may seem like a good deal, but they are not worth the money..