DAMO 1/2 inch Dry Wet Diamond Core Drill Bit for Concrete Granite Marble Hole Saw

It's easy fast clean cuts and the price it's okay

Used this to install a new drinking water tap. Went through and inch thick granite countertop like butter. Make sure you start the hole at an angle, and keep the bit cool by dipping it into water from time to time. When I say start the hole at an angle, I mean hold the bit at a 45 degree angle to the countertop and before you make contact with the surface, start up the drill at high speed. Then ease the bit down onto the countertop at the 45 degree angle until you make contact with the surface. Be prepared to brace the drill so it doesn't skip across the counter. Starting the bit at an angle greatly reduces the tendency for it to skip around. As you grind into the counter a little with the bit at an angle, you can start to slowly rotate it up towards 90 degrees while drilling. Go slow and eventually you will have a nice channel for the bit to stay in as you start drilling down through the countertop. Good luck!

Based on the reviews I purchased this bit and I'm glad I did. I only needed to drill one 1/2" hole in my desktop to mount the articulating arm for my monitor. It did the job cleanly and easily. Since I was only drilling one hole we did not use water, and it appears the tool got quite hot... but it did a fine job and took less than 10 minutes using a 28V cordless grinder. If you plan to drill more than one hole I would recommend using water to keep the bit cool. I was a bit apprehensive about drilling into this hard 1-1/4" material but this tool made the task easy.

Takes like 5 min. To go thru granite

I needed a half inch hole through 3/4 inch of granite and this fit my Craftsman grinders shaft. It wsa a good decison as I got a perfect hole in aobut ten minutes. I used a piece of hardboard with a 1/2 inch hole duct taped to the counter and had my wife spray water on the bit as I ground. Very easy and it looks like there is a lot of life left in the bit. PS the hole is a bit oversized but that did not affect the installation of the faucet.

I was installing an under sink water purifier and I had been using a mason bit. It was taking forever and I had to constantly be careful of chipping. This bit saved me so much time and made a very clean cut. Make sure to buy the adapter to go with it. I got the Drilix adapter.

Worked great on my granite counter top for my new R.O. Water faucet.

Quality product worked on my Grinder and drilled the hole into the granite clean and very quickly just a couple of minutes. prior to using this bit it would take much longer. I would highly recommend this product.