From Porsche 911: Forever Young, by Tobias Aichele
"To be precise, the Fuchs wheel was formed by the following steps. A pressed piece of stock was forged to make a forging blank. Next, drop forging the blank produced the ventilation holes and deburred the flange. A further drop forging step resulted in a split flange, before the workpiece was widened by rolling. And here is the secret advantage of this complex manufacturing process: the Fuchs wheel stayed in production for so many years because it could be rolled to any width desired. The forming process resulted in a wheel with a completely finished inner side. The outer, visible side of the wheel was turned on special lathes, which resulted in the smallest possible wheel imbalance. A carefully developed surface finish -- polishing, anodizing, and painting -- permitted different design variations over the years and assured high corrosion resistance."