Advertised to drill a nice, clean hole in CMU, a soft and hollow concrete product. To put it simply, even with a very high hammer drill at the right RPM and pressure, this hole saw drill bit struggled to move forward and eventually broke, bits of the broken blade flying off, hitting my goggles and burning my face. I will be posting a picture of the destroyed blade soon but wanted to post this asap so others know it is unsafe as the CMU concrete block is advertised. Essentially this gives you a…