Heavy duty steel. Several shank sizes available. Pilot drill included with arbor. WARNING/ADVERTENCIA: CANCER AVOID INHALING WOOD DUST CANCER EVITE INHALAR POLVO DE MADERA www.p65warnings.ca.gov , www.p65warnings.ca Some dust created by power sanding, sawing, grinding, drilling, and other construction activities contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. Your risk from exposure to these chemicals varies, depending on how often you do this type of work. To reduce your exposure, work in a well-ventilated area and with approved safety equipment, such as dust masks that are specially designed to filter out microscopic particles.