JINGLING 2.5mm Diamond Drill Bits for Glass, 3/32" Diamond Drill Bit, Hole Saw Drilling Tools for Stone Tile Pack of 20Pcs

The tip of my bolt extractor snapped off when using it on one of the bolts on the underside of my lawn mower deck (the bolt head broke off), the bolt was old and rusted. Two days of penetration oil didn't do enough. So, the bolt extractor was used to get the bolt out...that was a no-go when the tip snapped off and was fully stuck in the pilot hole. These bits were purchased to see if they'd help in wearing down enough material to get the bolt extractor tip out before I drilled through the bolt and re-tapped it. The extractor being a far harder steel made using my usual drill bits a no-go in attempting without something like diamond coated hole saw bits. So, with as many as come in this pack, I figured why not? It's cheap and a useful test. I went through about 4 of these, ensuring I kept the bits cooled with a container of water (dipping the bit in ever ~5 seconds of drilling), over the course of about an hour. Gotta go slow, don't apply more than a very light pressure if any, let the hole saw do its thing by abrasing the metal slowly. Worked great, the extractor tip fell right out eventually, and I've got a bunch more of these for the next time!

Five star! I've only used one drill bit but so far this FAR outperforms the dremel glass drill bit. I have so far drilled more than 15 holes with the first drill bit of the package. 15 holes and it still has some life! I have drilled through rock, glass, and shell. In comparison the dremel glass drill bit was only used on glass and I maybe drilled 12 holes before it was useless. The size of the hole this bit makes is a little larger than I expected but I take it into consideration for what I'm drilling. The one complaint I read about and is a bit of a problem is the length of the hollow core of the bit. After each use I have to use a metal pick to punch out the stone or glass piece that is in the bit by sticking a metal pick through the small side hole. And if whatever you're drilling through is thicker than the hollow core of the bit you have to stop short and break off the nub inside the hole before proceeding. This bit is so much better and cheaper than the dremel bit that I will happily adjust for the two issues I mentioned above.

Very good drill bits, they serve their purpose. I used them to drill river rocks and although the process is slow, it was possible.

Can I give this a ten star review? I have tried every bit available for drilling holes in glass. I’ve used full sized drills and I have sued my dremel flexi shaft. THESE BITS ARE THE ONES! Most bits wear out quickly after a few pieces and take forever to get the job done. One bit drilled all of these pieces in less than five minutes. And there’s more use on the bit too. Long lasting and perfect. Worth every darn penny!

I was prepared for these bits to be use-once-and-toss. But the first bit has already breezed through four holes, one of them in fairly thick glass.

I'm a little mixed about these tips. I shape, cut and drill into stones and rocks. What I've experienced is that sometimes these bits are great and they're efficient and make clean cuts etc. Other times, like my second order, it seems like the bunch is faulty at best. I just opened them to use and already one is beyond blunt/ stripped and another the tip literally BROKE OFF. See pictures. I think I'll purchase a different brand moving forward.

WORKS LIKE IT SHOULD FOR A GREAT A PRICE.

I drove through 75 1/2" opal beads taping slowly with my drillpress

JINGLING 3 mm 1/8" inch Diamond Hole Saw Core Drill Bit 's outdo what they advertised. I used the diamond bits through quartz crystals & they worked really well I'm impressed !

Great for drilling through our beach rocks, sea glass and shells. Found these to work best so far. We use in our drill press and they last a long time. I ordered more.

Good to start with this to do a small hole and finish with a bigger bit. Good to have many because they wear pretty fast even with watering when drilling. Did the job for me with multiple bits

These have become my go-to bits for drilling pendants. They do a great job of cutting smoothly and cleanly through any Stones, even quartz. Being a hollow core drill bit, they do need to be cleaned often. I use a push pin to clean out the core. I find they are generally good for five to ten pendants.

Keep the bit wet and you'll be fine. Looks cheap, works great. I drilled 6 holes with 1 bit in ceramic floor tiles to see how far a bit would go