Made from Carbon steel and precision machined. Auger has a spiral point, single flute. Ideal for quick, clean deep holes. Must only be used with torque control drills to prevent wrist injury. Dimensions: D=12 mm Overall length=155 mm Shank Diameter=1/4 inch hex Shank Diameter: 1/4 hex Diameter Metric: 12 Overall Length Metric: 155