Disassembly analysis of self-tapping screws for sheet metal joints

Self-tapping screws are essential components in the assembly of sheet metal for mechanical products. These screws, thanks to their ability to create secure and durable joints with minimal preparation, are commonly used in many industries such as consumer electronics, home appliances, automotive, and industrial equipment. In this study, experimental studies have been performed on mechanical joints of sheet metal parts that employed self-tapping screws. Disassembly time has been assessed through several tests, considering variations in screw geometric features (head type, diameter, pitch, and length), the use of alternative disassembly tools (manual and electrical screwdriver), and different sheet metal thicknesses. In relation to the screw geometric features, the disassembly time was mostly affected by the combination of diameter and length (and consequently of the pitch) with limited influence of sheet metal thickness. The outcome of this study drives the design of mechanical joints for sheet metal applications in several products, providing design for disassembly guidelines of reversible joints employing self-tapping screws.