For smooth contour carving in wood, plastic, and aluminum, these bits have a ball-nose design. All are made of solid carbide for a long tool life and fast cutting speeds. The extreme hardness of carbide bits means they are brittle, so they're not recommended for use with hand tools. A highly rigid setup, such as a CNC machine, is necessary to prevent the bit from breaking. The spiral flutes pull chips up from the workpiece while making cuts; securely clamp your material before routing to prevent lifting.