30 Pack 1mm Diamond Drill Bit for Dremel Craftsman Rotary Tool 1/8″ Shanks Jewelry Beach Sea Glass Shells Gemstones Lapidary 30pcs.

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.