DAMO 1-3/8 inch Dry Wet Diamond Core Drill Bit for Concrete Granite Marble Hole Saw

I bought two of these diamond core drill bits to drill approximately 6 holes through granite countertops.They worked great.For the technique - I got some playdough and make a "snake" that I put on the counter and formed a circle that was pressed around the area I wanted to drillI filled that area with a small amount of fresh water and then started at a slight angle to get the bit "started" into forming a groove in the counter top.Once the groove is started, you can move the drill to a more conventional "top-down" position which levels the drill bit into the counter.The water helps to reduce airborne dust to almost nothing and helps to cool the tip of the drill bit (important).Slow to medium drill speed is also important as is stopping every few minutes to add some more fresh water - the mix of water and the dust from the drilling creates a friction component for the bit which helps the drilling process.However, be sure to clean out the ports on the tip of the bit every few minutes as they can get clogged with the water/dust sludge caused by the drill bit being in the water bath.Solid product and recommended based on my experience with it.

I used this with a corded DeWalt 1/2 corded drill. Make sure you buy the drill shank adapter if you go this route. I was able to drill a hole through a quartz countertop. I went very slowly, so it took longer than it probably should have as I was paranoid about cracking the countertop. Don't want to anger the wife.It drilled right through. No complaints at all. I started dry and used a PVC pipe to guide it straight in and on the marks. From there, I used plumbers putty to make a ring around the hole and filled it water for cooling and lubrication. Now we have a hot water tap!

This worked like a charm. I did 3 holes in 3/4 inch granite counter top with a friend keeping the area wet with an atomizer of water.I also put masking tape over the area to be drilled and marked the circle (using same 1 3/8 drill bit) with a pencil.This is what YOU NEED TO KNOW: START drilling the hole with the bit at about a 45 degree angle. The bit will cut right into the granite without skating. (The masking tape may help also). Slowly bring the drill bit to straight up and down position as you continue drilling. I did the three holes this way with no problem. You can go to YouTube also and see how it's done, "drilling holes in granite".I used a fairly strong electric drill motor (had to buy the adapter). Took about 2 minutes per hole. I used pressure but not a lot, I let the drill do most of the work. If you use a grinder instead it may go a little faster.PS I made these holes in my office counter top so I could more easily run all the cables (computer, printer, telephone etc.) If you are doing a similar "office" job you should check out the Amico Computer desk 1.3" flip top grommets (Amazon) that fit perfectly into the 1 3/8 inch holes and make for a totally professional finished look.

Bought this and a grinder for two holes I needed to make in the 1-inch granite countertop in kitchen. The first hole went okay - with occasional sparks, but within a few minutes we made the hole. The second hole took a lot longer - about three to four times longer - long enough that I had to stop three times to give my arms a rest. My conclusion is that the bit lost its sharpness after the first hole. Fortunately I don’t need it anymore and as soon as I can get it off the grinder the bit will be discarded. I don’t know what experience others have had with this.

This worked very well to go through 1.5" of granite counter top to put in a faucet for a filter/osmosis system. I used a large Milwaukee industrial 1/2 inch drill (w/o the hammer function) and it went through in about 10min w/o much wear at all. I occasionally stopped and cooled down the head w/a dip into water. It served it's purpose. The only hard part was getting it started w/o sliding around. I found getting up on the counter - using the 2nd stabilizing adjustable handle - and positioning myself over the drill hole stopped the sliding a lot.

I used this to drill an epoxy countertop and it went through like butter. I will buy more bits from this company in the future.

I used this item to drill three holes into tile. It worked very well and did not appear to be worn after the completion of the three holes. I'm sure it would be good for many more as long as the bit is kept wet while cutting. Note that this item does not come with the chuck to hold it in the drill and the threads are different from standard wood hole saws. I made my own chuck from a bolt. Otherwise you would need to buy a chuck separately.

The bit is sturdy enough, but the shaft that you buy extra on this website bent on the fourth cut into tile!! Because this was special ordered here, I wasn't able to run out and replace it on the job (which had me cutting 52 holes in tile and the same number in marble for a custom inlay contract). Instead, I had to go to Home Depot where I bought what felt like a very light weight Milwaukee bit and shaft... What I found was this setup from Home Depot was better than this hefty DAMO cutter. The Milwaukee bit had more water channels cut into it - giving it less teeth but a much cooler cut, and also a finer edge so the cuts were diamond sharp. As compared to this rather cumbersome thick edge on the DAMO. The four small water channels on the DAMO quickly got filled up with tile crud too.... In other words, save yourself some bucks and heart ache maybe too. Get the Home Depot or Ace Hardware or such Milwaukee cutter, and if anything goes wrong on the job, it's just a trip to the store...