They replaced my Harbor Freight set, one of which broke when I was drilling through a standard household junction box. There used to be a video on YouTube of a DeWalt Impact Ready treadle drill showing them drilling through a quarter inch slab like it didn't mean anything. I used one of these to drill through the steel frame of my pickup truck with a Bosch impact wrench. I had to drill a few large holes when installing the hitch. Before using, I pre-drilled the holes according to the assemblyβ¦