At the beginning of this production step a central hole is drilled into the round rod of stainless steels or nickel alloy prematerial. This extrusion billet will be heated up to hot forming temperature and pushed through a die and over a mandrel followed by air cooling or water quenching.
This economic technique produces hollows as mother tubes for further cold forming processes like cold pilgering, cold drawing, as well as the final products if hot finished pipes and tubes are required.
