Electroplated carving points  can be used on many materials such as glass, stone, hard wood, ceramic, shell and porcelain. To get the best life and usage out of your burrs use with a little water before or during use. Can be used in any rotary tool or flex shaft. They are a great buy for beginners just starting to enter the carving field. This 10,20,30,50 piece shapes offers a large variety of cutting options.