Review on SHDIATOOL Diamond Coating for Concrete, Marble, and Granite Surfaces by Michael Hale

Using a Milwaukee 4 1/2" angle grinder, then a 7" Dewalt angle grinder and a 6" extension, I cut to length and diameter This drill bit (4x4") gouged through a solid concrete wall in less than 5 minutes. Using an extension cord the bit started getting stuck in the hole with my smaller angle grinder, this may be my fault as I used a spray bottle of water the concrete grout slowed the bit down. Using a larger angle grinder and this drill bit I cut through a tough 10" concrete wall in minutes without using water, it saved me from renting a core drill for the day and I still have this amazing drill bit when I need to cut more concrete. The diamond edge is still as good as it came out of the box.