B208SM300 - Double Cut Carbide Burs Cone Shape 1/4? Shank Cone 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 1/4 Length 2 / 50.8mm Diameter of Head 1/4/6.4mm Length of Head 1 / 25.4mm