Kutzall burrs are coated with hundreds of sharp tungsten carbide teeth that remove stock quickly. They are not prone to loading, but may easily be clean with our bur solvent or you can use a gas torch to burn away debris; the heat won't harm the teeth. These burrs can be used on wood, soft stone, cork, rubber & polyurethane. Recommended speed range: 5,000 - 25,000 rpm. Coarse grit coating. Size: head 1/8" dia. x 3/4" long. Shank - 1/8" dia.