Flow drilling is a non-cutting method for drilling holes into metal, in which the material is melted by adding high pressure and frictional energy.
Flow Tapping is also a non-cutting method. The screw-thread is rolled.
Flow Drilling makes use of a highly heat-resistant hard metal pointed object. This is pressed against a workpiece at high speed. As a result, locally developed a lot of frictional heat, whereby the material of the workpiece reaches a temperature where the metal becomes liquid. The flow drill collapses, as it were, through the workpiece, with the formation of a hole. The liquid material does not get lost, but forms a bushing, The bushing has a length of the original wall thickness about three times.