Flow Drill ScrewsThrough the central tightening shaft of the FDS device, the high-speed rotational motion of the servo motor is transmitted to the screw, which acts on the sheet materials to be joined, generating frictional heat. Under the action of a huge axial pressure, the materials undergo plastic deformation, and a cylindrical through-hole is formed under the extrusion of the flow drill screw. Then, the tip of the screw pierces and screws into the sheet materials to be joined, enabling the processes of drilling, tapping, and tightening to be completed in one operation on the FDS device. Finally, a fully meshed threaded connection is formed between the sheet materials and the screw.