Abstract: A rotary shear attachment and tool for laminated plastic and other materials is disclosed. The shear attachment comprises a frame which is fixed to an existing motor case and has an upper and a lower portion spaced apart and separated by a central portion. Driving and cutting wheels are positioned on the frame and are rotatably mounted for cutting the plastic and other materials. A chip breaker is positioned on the frame to break up the chip formed by the shear attachment and the frame has means associated with it for diverting one side of the plastic being cut in a direction away from the plane of the other side of the plastic. The novel rotary shear attachment may be incorporated into an improved rotary tool, may be incorporated into existing rotary tools and may also be used with a novel table for cutting a large sheet of plastic at a job site.