15 Pcs Diamond Drill Bits for Ceramic, Diamond Hole Saw Drill Bit Set Kit, Premium Glass Drill Bit for Bottles,Pots, Marble, Granite Stone, Tile Cutting 0.23 Inch - 2 Inch（6mm - 50mm） YLYL

Understand that these are all in metric sizes and this purchase was for the smaller sized bits. There are many sizes to choose from in this kit, from I think 3mm or 1/8 inch equivalent up to I think 24mm or like 7/8 inch. The sizes are laser etched on the shafts and are a little difficult to see, but the holes that they make are relatively smooth rather than just a sharp edge. The reason is that the bits are simply metal tubes that have one end dipped with metal covered crushed industrial diamond, much like sprinkles on an ice cream cone. With this said they are not lab quality sized bits, and have some cutting surface disparity due to the various sizes of chunks around the end, and this disparity will create a more rounded or smoother edge on the hole that you cut through the glass. Start out slow and at an angle with just the weight of the bit against the glass, and spin the bit against the glass until a little edge develops (I used a rechargeable drill), then add a few drops of water and start to reduce the angle and the edge starts forming a circle on the glass. Slow and steady wins the race!! This is glass, and super tiny pieces of glass are now being broken off of what ever you are drilling through so wear a mask, and have a removable work space that you can just wipe and clump up into a ball and throw away, like some damp newspaper that the wet paper will keep the super tiny glass fragments/shards from blowing away and you can just crumple up and throw away the mess with minimum wiping. With this set I managed to drill a 1/2 inch hole in the side of an aquarium for a water overflow, on one of those 2 1/2 gallon rectangle super thin glass aquariums with the black plastic frame, that still had some fish in it (do not recommend this). The hole was a success, the fitting has been installed and still the aquarium has fish in it (that suspect nothing.) Slow and Steady, listen to the screeching of the bit against the glass, if too much screeching you are either too fast or pushing too much. Slow down, add a few drops of water, and then continue on until you start to see the point where the water starts running down the glass on the other side, then slowly continue on until you have a hole drilled through whatever it was you were drilling. Note: I do not know what it would do to tempered glass, from what I know this would probably shatter any tempered glass the instant the bit scratched the surface. My use with these bits has been just plate glass and bottles. Good luck.

I bought these to tap a hole into some wine and liquor bottles, so as to make an unusual Christmas ornament. Drill thru easily and did not crack the bottles

I bought this 15-piece diamond drill bit set for some tile and ceramic work around the house, and I can say they definitely do the job. The variety of sizes in the pack is excellent, covering almost any small to medium hole you might need for bathroom fixtures or kitchen backsplashes. They cut through ceramic and glass cleanly as long as you use enough water to keep them cool. In terms of durability, they don't last very long. You might only get a couple of good holes out of each bit before the diamond coating starts to wear off. However, considering the very low price for a 15-piece set, I knew exactly what I was getting. It’s much cheaper to buy this entire pack and use them as 'disposables' than to buy one single professional bit that costs five times as much. If you are a professional contractor doing this every day, you might want something higher-end. But for a DIYer or someone with a one-time project, these are perfect. They are effective, affordable, and get the task done without breaking the bank. Just remember to use low speed and plenty of water, and they will serve you well for the price!

I drilled a hole about an inch in diameter and an inch deep in very hard basalt stone. It took only a few minutes. It works best if drill is cooled and lubricated with plenty of water. Not much force is needed, and fairly fast turning speed. Drill wears its way into the stone, and water washes away the powdered stone. Drill bit is limited how deep it can drill, and I used a chisel to break out the core, a few taps from the side. Diamond-coated drill bit cuts by wearing a groove in the material being cut. Photo with hammer and chisel also shows the removed core.

Just used this to drill holes in clay pots for the wife. I was surprised with the size, variety and number of bits for the price, as well as the quality for the cost. Bits worked great and finished in no time. Be patient at the start because this type bit will dance on you. Thank you for a quick delivery and a good deal.

Versatile Drill Bit Set That Struggles With Durability I picked up this 15-piece diamond drill bit set mainly for ceramic tile and glass work, and while it’s very versatile in sizing (ranging from 6mm to 50mm), I came away with mixed feelings. On the positive side, the set gives you a lot of options—you’re covered for small holes in glass bottles all the way up to larger cuts in tile or marble. The bits fit securely in my drill, cut cleanly when kept wet, and the price point is attractive for such a wide assortment. That said, durability is the main drawback. The diamond coating seems to wear down quicker than I expected, especially when drilling into tougher materials like granite. A couple of the smaller bits dulled noticeably after just a few uses. I also noticed that without steady water cooling, these bits heat up fast, which makes chipping and uneven edges more likely. These aren’t bits I would rely on for a large project, but for occasional home jobs they get the job done. Bottom line: A decent starter set for hobbyists or light-duty projects with tile, glass, or ceramics. If you’re tackling harder stone or frequent jobs, you’ll probably need a more heavy-duty, longer-lasting set.

They cut holes that are clean enough for my tile projects. I cut a hole in a scrap tile, then used it as a template to keep the saw bit steady. Packaging is the set put in a plastic bag. But the price and usability more than offset the packaging.

I am using these to drill holes in the bottom of my planters that do not have drain holes and they work perfect. Be sure to have water on the bottom of the planter. When drilling the hole, it helps keep it from getting overheated and breaking the pot. I do dump the water off after it starts. Looking cloudy and put freshwater on on some of the parts. I do have to lean the drill sideways to start out on getting it locked in place before standing it straight up. And then start drilling