Features:

  • Diamond coating maximizes performance and retains a sharper cutting edge than traditional carbide or bimetal hole saws
  • Side holes allow for easy slug removal after drilling
  • Perfect set for cutting accurate holes in a wide variety of materials such as glass and ceramics
  • Nickel plating on these bits maximizes your tool’s life with great resistance to corrosion
  • 5pcs 12mm 1/2" Inch
Worked awesome on a granite counter top for a reverse osmosis water filtration system! Super easy!

I love these bits! I used them in a cordless drill to drill a hole through a granite counter top to install an APEC reverse osmosis water filtration system. It was so easy! I made sure the bit remained in a pool of water during drilling to keep it cool. I ran the bit at 2000 rpm, but I'm certain it can perform just fine at lower speeds. The bit itself is a little over an inch long, but the granite plug inside broke off, so I was able to drill deeper than the internal depth of the bit. My counter was about 1-1/8" thick. I purchased the 5-pack just in case the bit would wear out, but the bit showed no signs of quitting any time soon. I only used 2 bits because I didn't want to spend the time to remove the granite plug from the first bit right away. I'm so glad I didn't have to spend a ton to drill through granite.

Drilled a granite countertop. For the money, you can't beat it.

For the money, you can't beat it. I got this for drilling my granite countertop to install an RO water filtration system. My instructions said I needed a 1/2" hole. I used a regular cordless drill. It took 3 bits, but I got it through. I marked the hole with an indelible marker then built a little pond about 1/2 inch deeo around the mark. I used plumbers putty to make a good seal. I filled that with clear water so I could still see the mark as I started drilling. To keep the bit from "walking" I held it steady and started drilling at an angle on the edge. This started a little groove, then I slowly got the drill to vertical. I drilled until the water started boiling. Yes, it is hot. Then I swapped bits. The bit I took out had some granite in it. This is needed so you can get all the way through. Perhaps I didn't need to, but I swapped bits again until I used three. I kept the RPMs at the upper end of the drill capacity, but not all the way as fast as it would go. ...nice clean cut.

Smaller Than 1/2" But Very Useful

Needed to cut a 1/2" hole through hard wall tile to mount a TV employing a strap toggle that had to have a true 1/2" hole. These diamond coring bits are metric and read out at 11.66 mm or .46". Even then it's a lot easier to core the hole with this little diamond bit, then open it up with a standard 1/2" carbide bit. I cut a small 1/4" piece of plywood and drilled a hole in the plywood close to the .46" diameter of the diamond bit. I taped this guide to the wall so the bit would not wander. I dipped the bit into a glass of water often to cool it after every few seconds of drilling to extend its life.

Works great

Having never tried drilling holes in glass, I purchased these with a specific task in mind. I was quickly and easily able to drill holes through 1/2 inch thick glass candle holder so that they could be used as planters. With a little water poured on the drilling site every few seconds, the bit cut quickly and there was no discernable heat build up.

worked well, can't beat the price

I bought these to drill a hole in a granite countertop for a drinking water faucet (reverse osmosis filter system). I couldn't get the hole started with this bit alone. I had to use a 1/2" pointed masonry bit to get the hole started in the right place. Once the masonry bit made a big enough divot in the granite, I switched to the diamond core bit. All in all it took about 15 minutes of drilling to get the hole through. In that time, one bit went dull, and another got a granite plug stuck in it. I might have been able to get it out, but I just switched to a new bit and finished the hole. Make sure to make a little pool by putting a putty ring around the drill spot and filling with a bit of water.

One Bit Has Drilled Six Pots!

I bought this set because I didn't think one bit would get through the several pots I needed to drill drain holes in. Well, I was wrong. One bit has now drilled six pots and still has some edge to it. I suppose my pots are soft (they certainly were cheap), but this set is a bargain.

durable and worked great for me

I needed to drill 2 half-inch holes through about 1.25" granite countertops. I only used one bit. It didn't look like all that much had worn off the bit by the time I finished but it did seem like the cutting action had slowed down. I just made about a 2" circular dam out of plumber's putty around the center of the desired hole, filled it with water, and drilled away nice and easy and medium drill speed at most. You do need to start at a 30 degree angle and gradually straighten up to vertical to make it easy to start a groove where you want the hole without it wanting to walk away.

Wow, I am so impressed with these bits

It's been awhile since I bought these bits. I finally tried one out today and all I can say is "WOW"! I drilled 26 bottles and had no trouble at all. I filled the bottles with water and corked them kept the drill bit wet with a spray bottle. A cradle for the bottles to set in is very important, and just let the bit do the work, no pressure. The last I did went just as good as the first one. So I really can't say for sure, exactly how many bottles one bit will drill maybe 50 depending on the type of glass. Some of the colored bottles seemed a little harder so took a little longer. I am so impressed with these bits!

They are amazing. I can drill about 10-15 bottles before having ...

Purchased these drill bits to use for drilling holes in wine bottles. They are amazing. I can drill about 10-15 bottles before having to change the bit. Just as a tip; when drilling holes in bottles, it is best to keep the drill bit wet, it makes the job easier.

Works better than I could have imagined

Cutters work great. Do a little research before you try to drill glass. Please take the advice of others who have tried it and worked out the kinks firsthand. Drill MUST be immersed in water while drilling. Use playdough, modeling clay, or plumbers putty, rolled into a rope and pressed down around drill area to create a small well to hold water. pour water into well and then drill SLOWLY. About one minute to cut thru a wine bottle. Have drilled 11 wine and liquor bottles with same bit and it still drills as well as the first one. I use a tabletop drill press which helps, and a V-shaped block under the bottle to stabilize it. A large piece of clay would work just as good under the bottle to hold it steady.

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