Review on 💎 Diamond Hole Drill: Perfect for Granite and Glass Surfaces by John Ghattamaraju

I used them to cut through hard Drilling granite to attach some studs to attach an outer ladder. The chisel allows you to drill a hole about 1" deep that wasn't deep enough so I used a small extension to deepen it ( I had to grind the shank to fit the extension.) I used a gallon milk jug with a small hole in the bottom to cool/oil the bit first, although after starting the hole I only drilled the hole (drilled vertically ) needed to be filled with water. I drilled four 2" holes with a 1" drill bit, no problem. It only took a few minutes to drill each hole (although you have to periodically remove the stone with the core to get deeper than drilling the first inch). without purchase.