Abstract: A drive configuration is formed on a fastening assembly which includes two working units. The drive configuration includes a plurality of operating regions and a plurality of driving regions. An engagement region is formed between every two adjacent operating regions. A fitting region is formed between every two adjacent driving regions. Either the surface of the engagement region or the surface of the fitting region forms a three-section arc structure which includes three arc walls. When two arc walls of the three-section arc structure of one working unit come into contact with a single arc wall of the other working unit, two engagement points are formed when each engagement region engages with each fitting region, thereby attaining a stable engagement, applying torque efficiently, and allowing a one-handed operating mode for ease of using the fastening assembly.

Abstract: A drilling fastener utilizes at least two sides jointed to form a shank. A corner point is formed between any two sides for outwardly extending a rib therefrom. The rib includes a cutting section extended outwardly from the corner point about an arc contour, and a arc section whose two sides respectively connect to the cutting section and the side. A cutting tip is formed at a convergence of the cutting section and the arc section and located at which the largest outer diameter of the shank is defined. An accommodating room is defined between each arc section and the side. Thereby, the auxiliary cutting provided by the cutting tip allows the debris to be swiftly extruded via the accommodating room, thence preferably decreasing the driving torque and preventing the workpiece from being damaged. The fixing efficiency after screwing is further promoted.