Tm 30 Pcs Diamond Burr Bits Drill Glass Gemstone Metal for Dremel Craftsman Rotary Tool 1/8" Shanks w/Box Tip

I needed to drill holes in some shark teeth...like most normal folks do on a daily basis, of course. In particular, I wanted small holes just large enough for wax thread. So, I found these bits and thought I'd give them a shot. I had no illusions that these would be heavy duty for the price and just hoped that a set of thirty bits would be enough to drill 14 holes. Well, I have to say that I'm impressed. Not only did they work...But, I drilled all 14 holes in fossil shark teeth using just one bit. So, after reading all the other reviews, this was far better performance than I'd expected. Here's how I did it. 1. I found a small round tin with 2" high walls to use to hold the water and base for drilling. 2. I packed some Plasticine modeling clay into the bottom to act as a grip to hold the tooth. 3. I embedded the tooth into the clay and put enough water to cover the tooth by about a half inch. 4. I put the bit in my Dremel and set it to one of the lowest speeds. This is important because I think a lot of people are running these too fast and burning the grit off. 5. I slowly drilled into the tooth and frequently backed out to allow the filings to wash out of the hole and to cool the bit. I think it took less than an hour to drill 14 holes through shark teeth around 1/8 to 3/16" thick. That is the pro...definitely worth the money. The downside - Don't expect all the bits to be drill worthy. I mean, if you are drilling any sort of precision holes, only half of the bit tips are true enough for accuracy. The rest are fine for grinding edges or maybe enlarging holes. Some are slightly bent and some are varying diameters...just not precision manufacture. So, don't expect anything amazing for ten bucks. But, I'd definitely recommend them.

I'm very pleased with these diamond bits. They have worked perfectly for me opening up and grinding holes in glass. They seemed at first to be too thin and fragile for what I was doing but so far are holding up well!

I got these to sand paint out of some very small corners, and they did the job. The only caveat is that the extremely thin metal warps a bit when when dremel gets going, and the tip makes a circle around an axis instead of spinning right on the axis. Once the tip was on the metal, i could press it into staying in place, but because of the extra pressure i also got a couple of unwanted grooves. Once I had a feel for how they needed to be handled though, they were wonderful for fine detail work.

Kind of cheaply. They are from China. Not that all products from China are bad but some are. This is an example. China! I know you can do better.

Excellent!

First time trying to cut into glass tile, the tip just bent. Tried different tips same thing happened. The others that didn’t bend would just not cut through the glass. This is very low quality. I should’ve went with the name brand

I make stained glass earrings as a hobby. I was looking for something to drill small holes into glass without breaking the bank. This is it. I don’t know what the negative reviews are talking about. Submerge your piece in water, use a dremel, drill at medium speed. Apply little to no pressure. I’ve gotten 15 holes so far outta one bit, and it’s still going. These bits work great for how cheap they are. Don’t listen to the negative reviews; buy them.

This item arrived first out of many. Super fast shipping!! These are the best inexpensive bits I have seen. The coating veries in thicknesses but there ready to do do the job!, Straight and well built at there core.. ( there not a blob of crap on a stick ) They all have threads where the metal/diamond was bonded, some are thick some are thin with the coating but way better than the cheap ones!... If you noticed in the pic the larger 3mm one's are machined down to Allow the 3mm shank to compensate for threads and a thick diamond coating for a final 3mm. That's why I ordered them and that's what I received.. I inspected each one with a loop and am very satisfied with this product for the price.

Work good

These bits are smaller than I expected but fit fine in my Dremel. It's nice that there are 2 sets. They work for my purposes in helping to shape small pieces of glass to use in mosaics. I am not sure how long the diamond grit will last but there are so many bits I am sure it won't really matter.

They are not good drill bits. Not good for drilling glass, came apart, like paper when it is wet. Would not go through glass, when my dremel drill was on a high speed. Would not recommend.

Value

Low quality .they wear out pretty fast .u get what u pay for .