Review on DAMO Diamond Concrete Granite Marble Cutting Tools: Efficient Industrial Drill Bits by Nathaniel Collins

I bought two of these diamond core bits to drill about 6 holes in granite countertops. " which I placed on the counter and formed a circle pressed against the area I wanted to drill. Once the groove has started you can move the drill to the more usual "top down" position Moving motion that aligns the drill with the countertop surface Water helps keep airborne dust to a minimum and helps cool the tip of the drill (Important) Slow to medium drill speed is also important as you will be stopping every few minutes You may need to add more fresh water - a mixture of water and dust from drilling creates a friction component for the drill bit which controls the drilling process. However, clean the drill bit openings every few minutes as they can become clogged with water/dust residue , which arise from immersing the drill in a water bath in my experience with it.