Material Type:Extreme - Very Coarse | Size:Head Diameter: 1⁄4", Head Length: 1⁄2" Kutzall tools are fast-cutting and long lasting, designed to work easily and efficiently where other conventional tools fail. Their tungsten carbide coatings consist of hundreds of extremely sharp teeth that rapidly remove stock and last 7 to 10 times longer than high-speed steel tools. They are not prone to loading but may easily be cleaned with solvent or burned clean with a gas torch. Whether you are a casual hobbyist or professional craftsman, Kutzall's durable carbide coatings will last job after job. All Burrs are used for various carving, hobby, industrial or do-it-yourself applications in flex- shaft tools or popular hand-held grinders with collets or adjustable chucks. Tool diameters are approximate and do not include the thickness of the coating. When it's your special hobby, do-it-yourself project or industrial application, Kutzall will provide you with the effortless control and superior performance you demand. With over 50 years of experience, Kutzall has long been the leader in the industry. When you need to remove material in hurry but still require precise control, there are no better tools for the job than Kutzall Extreme Burrs. The Extreme Burrs come equipped with a rugged, very coarse coating applied by fellow craftsmen. The aggressive, razor-sharp, tungsten-carbide teeth hog material away with unparalleled efficiency, while also resisting loading. This lets you spend more time carving, and less time clearing your tool. Recommended Max RPM is 25,000.