Dynabrade Pencil Grinders are an ideal tool for use in casting houses, effective on cast parts of aluminum, bronze and brass. Quickly and efficiently removes gates and parting lines in cast parts. Adjustable tool speed from 5,000 RPM to 25,000 RPM. Collet cap has tactile grip to protect operator from rotating collet, and allow fingertip control. Changing of attachment is achieved with easy, two-wrench maneuver. Unique housing shape allows tool to be held as a traditional Die Grinder.