[JEllis]

Found this on edmunds.... not sure if its relevant it or not.

Forged wheels are not all alike. If you were to squeeze a slab of metal and then machine away anything that didn't look like a wheel, you'd end up with what would technically be a forged wheel. This is the way many forged wheels are made -- a billet or forged solid metal pancake is CNC-machined all over, and out pops a wheel. However, in machining all the surfaces of the pancake, those critical grain flows in the microstructure are interrupted, and the strength of the finished part is thus compromised.

The way Rays forges their wheels is far more involved and results in a near-net shape part (see below for a visual approximation of the resulting grain flows) that requires little machining. They call their process mold form forging, and it is a type of progressive-die forging.

Here's how Rays process works. A slab of 6061 aluminum is heated and forged in order to increase its density. Then the slug is forged again to flesh out the features on the face of the wheel. Next, Rays applies a 10,000-ton press -- theirs is said to be the highest-tonnage press anywhere in Japan -- to the slab while it is spun, refining the wheel face and forming the rim portion. This working of the metal strengthens it.

Any remaining metal between the spokes is then punched out, then the rim region is cold-spun and formed. After a heat treatment is applied, the details of the wheel are finish-machined, magnafluxed, shot-peened and painted. Many of the wheel's primary load-bearing features require no machining at all, so the grain remains unmolested.

As you might imagine, Rays' mold form forging process is capital- and knowledge-intensive, and the resulting parts are expensive. According to the company, BBS is the only other wheel manufacturer on the globe with this kind of capability.