Super-hard Carbide Burrs used in a high-speed die grinder can really make tough jobs easier. Grind weld beads, shape parts, smooth rough castings, port cylinder heads. All burrs have a 1/4in. dia. shank. Burr sets include: cylinder pointed, tree-shaped and rounded nose. Individual burrs are tree-shaped. All 2-1/2in. - 3in. Carbide Burrs are individually packaged. Most commonly used on Steel and Iron. Use (46029) for a Tree Shaped Burr for Aluminum.