JINGLING Diamond Hole Saws 0.5mm Cylindrical Grinding Bits Jewelry Tools for Stone Pack of 30Pcs

I did not have very high expectations, but needed something super small to ground out a broken 2/56 tap. They performed better than expected. Some seemed to last longer than others and some last 3x longer than most. They definitely require some good hand feel, because to much lateral pressure and the end will snap right off. I also found that running cutting oil while I worked for cooling to increase the life x3. Definitely worth the money for my needs. Don't get upset that they break, they do take some practice to get the hand feel just right. I still break them, but typically because I start rushing or inattention. Good luck

I needed to make sure I could get a 1mm diameter for drilling in my seaglass. These are amazing for thicker pieces that gives me a nice even hole. I only use with water, in a tin with a dense foam behind so nothing overheats. I have drilled through many and still on my first bit!

For their size, the ends do break pretty easily, but that's expected due to the laws of physics, TBH. When they break, there's still enough end left to be usable, just can't go as deep with them. When being really gentle and applying a mild force, they will last a while before you accidentally force them too much and break the bit, not the bit's fault. These are exactly what I needed to connect two 0.5 mm holes, making an elongated opening (windows for plastic models). Great value for their size, would definitely buy again.

These work well but break easily, but that's kind of to be expected considering how fine a tip they have.

These are alight .. they work...they just wear out quickly. I can wear one out in a moonstone (for example) in about 20-25mins tops.... so....

Perfect

While I recognize that the tips are extremely thin, which is precisely why I purchased them, I did not realize how utterly brittle they are. In another review, someone mentioned being able to work on a few pieces of jade before they break, so I thought I would have better luck. I figured if I used them on the solidified epoxy dough, which is only a little tougher than dried clay, they would last for a while. Wrong. I had bit after bit break as I worked on the same material you could scratch with a butter knife. These are almost useless for any given purpose that anyone could come up with. I will never purchase anything like this again unless they are made of something stronger. I would advise anyone who is thinking of purchasing these for some fine detail etching to look for something else.

They are very small. Some got through several stones and some wouldn't get through 1 before breaking but not a bad price for as many as you get. I used them to drill through rubies I got for making jewelry. Not bad for the price.

Great product use for podiatry.

They seem to cut through glass quite fast. Just before it gets all the way through you should flip the glass over to drill from the other side to get a clean hole on both sides. If you go all the way through from one side it will punch out a small divot on the back of your glass .

Look like good quality bits.

I had been using a different 0.5mm bit to drill rocks ( quartz and amethyst) for pendants. Would get perhaps 10 holes from each bit. Ran out and switched to these. Using the same way (Dremel and ice water ), lucky to get one use or break on the first use, when using these bits. Seem very brittle compared to what I was using ( those other ones no longer available on Amazon). I will try to find something else. Getting one use, or worse ( bit breaking in the rock first time ) not good.

Good and helpful product with lapidary project, fast delivery