In order to produce all these bulging pipes, a hammer and a mold are sufficient. Please request Video. Twisted pipes are actually used in modern electricity poles. Period period is famous in different countries. My late uncle Ahmet Faruk CENGIZ and my father Ferit Celal CENGIZ saw the system that had built by a craftsman in the village and they adapted the system with the molds in mind that this knotted pipe could be produced in the power hammer mill. They produced 225 pipes per day with three rams and sent them to Gaziantep city. Some people claim to be a special machine for this, not a hammer, but I can help you as a person who knows the method, pneumatic hammer can do this work. At the same time, the ram is used for the tapering and diameter reduction operations. I will send video to you if there are video requests.
Soner Faruk CENGİZ