90-degree cone burs debur countersink holes and bevel and chamfer edges that have a 90° angle. Cone-shaped burs have straight tapered sides for smoothing beveled and chamfered surfaces, while the short cutting area maneuvers into counterbored holes. Cutting edges are made from carbide, which is a hard material that resists wear and limits heat. Carbide burs attach to rotary power tools such as die grinders, high-speed engravers, and pendant drills.