Step 1 The Fdrill comes into contact with the material using relatively high axial pressure and rotational speed. The generated heat makes the material soft and malleable enough to be formed and perforated. As the Fdrill pushes into the material, some of the displaced material forms a collar around the upper surface of the workpiece. The rest of the material forms a bushing in the lower surface of the workpiece. All this happens in a matter of seconds. The resulting collar and bushing can be up to 3 times the original material thickness. The diameter of the bush is accurately determined by the cylindrical part of the Flowdrill tool.
The process does not disturb the material’s internal structure. As a result; the formed bush is remarkably strong and can be used for bearing sleeves or, when threaded in a separate process, can provide high torque threaded surfaces with very high pull out strength specifications.
Step 2 The Ftap creates formed threads by material displacement. The material flows into the thread depression and crest of the tap.