The Kutzall burrs are designed to provide fast stock removal with an outstanding finish, thanks to exclusive tungsten-carbide coatings that make them the best value in the industry. The 1/4" shaft burrs are used in flex shaft tools, hand grinders, or other machinery using collets or adjustable chucks. They are not prone to loading, but may easily be cleaned with solvent or burned clean with a gas torch. Heat generated from the torch will not harm the teeth. Kutzall burrs are handmade in America (the Motor City suburbs, to be exact!).