Thermal tapping technology development at Kalfém Kft
Flow-drilling or thermal-drilling technology makes it possible to make high-strength threaded holes for sheets and thin-walled pipes without the need for material addition or removal. Suitable for replacing welded nuts, high strength holes, threaded joints, bushings.
Generally, drilling operations are defined as material removal with a regular tool edge.
The process is easy to understand because, like friction welding, frictional heat plays a major role here. The drill bit, which can be grasped on any machine capable of applying relatively high axial force, must be rotated at high speed and pressed against the workpiece to produce heat due to friction between the tip of the drill and the part. The temperature of the tool can then reach 650-700 ° C, and the workpiece can be 600 ° C in a small area around the contact zone. At this temperature the material will be sufficiently soft and the drill will easily pass through the component due to the high axial feed without the need for chip removal.
Szöveg forrás: https://www.cnc.hu/2012/11/folyatofuras-es-technologiaja/