I bought these after the smaller brand "Universal" broke. I was unlucky and the front bullets fell off its tip, after the restoration it suffered badly from the destruction of bricks and tiles, it is strong and powerful, and now almost 3 years later I can confirm that it is a bulldozer, I was able to drill through granite. or open holes through 30-year-old 8-inch concrete-cured platforms, this drill bit will go through almost anything it's given, a real performer.