US Patent 7971360 Powered hand-held metal cutter

A power driven portable sheet metal cutter includes a head with two blades that mounts to a hand-held electric or pneumatic rotating power unit. The fixed blade has a primary shearing surface that has a convex or radiused cutting edge, a convex or radiused bevel, and a convex or radiused body feature. There is also a clearance radius and a nose radius so that the cutter can cut a wide variety of shapes and configurations of corrugated building panels. A head with a right hand set of blades predominately cuts curves to the right, and a head with a left hand set predominately cuts curves to the left.