I've been reading about wheels and learned there are a couple of different ways they are made. You can get cast wheels or forged. There is low pressure (OE wheels) and high pressure casting (rivals forging). But the ultimate in strength and light weight, forged is the way to go.
However, in most forged wheels the final design is machined into the face using CNC mills. Which can create interruptions in the grain of the alloy and reduce its strength.
Then there is mold forging which I read is very difficult, very expensive and very few companies can do it.