B202SD300 - Double Cut Carbide Burs Ball Shape 1/4? Shank Ball Shape Carbide Burs The chisel tooth pattern not only minimises tool chatter but reduces the chip to a granular shape, in most materials. Al Cut for rapid material removal of soft materials such as: Aluminium, Brass, Copper, Plastics that would normally load other cuts Shank Length 2 1/6 / 55mm Diameter of Head 3/8/9.6mm