Diamond Hole Saw Drill Core Bit Kit Marble Granite Tile Ceramic Cutter Mandrels Saws 6mm - 30mm 6pcs Set

It was surprisingly difficult to find diamond core bits that were deep enough to drill through 3cm granite slabs in one go. These bits were deep enough, cheap enough, and good enough.I drilled about 10 holes with one of the bits and it did fine. Could probably do a lot more holes with it. Its not professional grade, but does the trick if you're a home owner and only need it for a few projects.They sell suction cup guides for these types of bits, but I don't think they work well. Its much easier just to drill a hole in a piece of wood (such as a 2x4) slightly larger than the bit and clamp it to whatever you're drilling and use it as a guide.The trick to these types of bits is to use low speeds (speed 1 on most drills), moderate pressure, and lots of water. It takes about 5-10 minutes of drilling to get through a 3cm slab. Don't rush it or you'll crack the slab or burn out the bit. Make sure there is a constant puddle of water around the bit. Heat is the main thing that wears these bits out. If its too hot to touch, its too hot to drill. A beverage bottle with a small hole drilled in the top does a good job as a water spray bottle while you're drilling.

I needed a .5" hole for a filtered water faucet I was installing. My quartz counter tops are 3cm, so I needed a hole saw deep enough to make this cut. I looked online for some guidance and ended up using the tilt-to-start method where you just let the tool touch the surface to be cut at a sharp angle until a small crescent is cut, then you slowly move the cutting head until it is straight over the surface. This worked great for me and saved the time of cutting a jig out of wood and clamping it in place as others have suggested. It was a bit nerve wracking at first (worrying about damaging an expensive counter top), but it was actually simply once I started. I built a dam around the area with plumber's putty and filled it with water to keep the drill cool during the cutting. I went slow and the hole was cut without issue. Took about 5 minutes (maybe less) from start to finish. I used a variable speed drill and kept it towards the lower end of the rpm range throughout. If you're thinking about whether or not you can do it -- I'd say give it a try. I'm fairly handy, but never attempted this sort of cut before. I would surely do it again myself, should the need arise.

I’m more than impressed with these bits I wasn’t sure if it could drill a granite where the installer said his bits cost $200 each and they can drill about 8 holes then they are dead. As you can see on the picture I was able to drill a 1” hole in about 5 minutes and it’s very clean hole for my drinking water faucet. If you are a DIY guy don’t ask questions go for them.

Drilled holes through porcelain and ceramic easily using an 18 volt Dewalt drill. Be sure to keep water on the bit.

Delivery was prompt. Good for casual use. Products arrived individually packed. Used for bathroom shower and sink remodeling.

Worked well drilling through granite counter top for soap dispenser.

There more cheaper and they work as it should

Like the multiple size. Good price!