I have a couple of rotary tools and like to cut with them, but most cutters and bits for that leave something to be desired, so I decided to try carbide ball-nose cutters. The best decision I've ever made regarding these tools. The end mills I like have 4 teeth and are small or very small. These cutters offer exceptional cut quality compared to those commonly sold as rotary tool cutters. They are extremely sharp, precise and cut cleaner than anything else. Of course, these mills aren't for that, which is a shame. If more people knew about these cutters, wood engravers around the world would be a lot happier. With these cutters I was able to draw detailed organic and geometric shapes and reproduce them very accurately, either freehand or using a mini cutter with my Proxxon. The level of accuracy is really good as these cutters don't try to wander too much. The presence of four sharp flutes and a round tip make these cutters unique for wood engraving/carving.