Abstract: A reamer screw having an elongated shank, with a leading end and a trailing end, at opposite ends, and having a self-tapping/cutting threaded portion at the leading end adapted for self-tapping and cutting an opening through a workpiece, and driving securely into a substrate, a torque formation at the trailing end for engagement by a suitable driving tool for the single function insertion of the threaded portion through the workpiece and into the substrate, in a single operation, a smooth shank portion extending between the threaded portion and the trailing end and having a length sufficient to extend through the workpiece, driving in of the threaded portion through the workpiece, releasing the workpiece allowing the threaded portion to be tightened up in the substrate, while the smooth shank portion rotates freely in the workpiece permitting the workpiece to be drawn snugly against the substrate without binding in the workpiece, and reamer formations formed by outwardly extending wing portions of the smooth