The "hot spinning" process is a process of heat treating metal rotating parts on a spinning machine. In this process, the high temperature of a torch is precisely applied to the workpiece, and the metal begins to shape under the action of a spinning wheel. This is because the professional tools on the spinning machine adhere closely to the heated metal surface, causing it to deform while spinning. After this step, the part can be shaped or necked to a smaller diameter as required. Remarkably, precise shaping of seamless shoulders can be achieved by applying only moderate amounts of force.