Abstract: The present invention may include a hole saw for use with a knockout of an electrical box, and the hole saw may include an arbor to clamp to a central shaft, a drive member to drive the hole saw, a saw blade connected to the drive member, a guide member to guide the saw blade. The guide member may be adapted to cooperate with the knockout of the electrical box and may rotate with respect to the central shaft. The central shaft may include a flat surface, and the arbor may include a set screw to cooperate with the flat surface. The guide member may include a cylindrical portion, and the guide member may include a narrow portion. The guide member may include a shoulder, and the saw blade may include a saw blade wall to connect to the drive member. The drive member may include a set screw, and a distal end of the central shaft may include a threaded portion. A fastening device may be connected to the threaded portion of the central shaft.