Quote:
Originally Posted by a5m
I believe they're referring to BBS and Rays being the only ones who mold forge their wheels vs others who machine forge, where they 'carve' a wheel out of a forged billet.
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IDK if BBS and Rays are the only ones, but yeah, this is more-or-less what I meant.
Here's my understanding, likely oversimplified and put in non-expert terms. Happy to have any necessary corrections.
"Billet" generally means the final shape is defined mainly by machining of the billet.
"Forged" is supposed to mean the final shape is defined mainly by the forging process.
All of this is shades of gray, of course. There's no bright line. Like all forged parts, forged wheels always start with a forged billet and end with machining. But there are usually intermediate forging steps to bring the billet closer to the final shape before machining (or to bring a partly machined item closer to the final shape before machining further). Those intermediate steps are where differences can exist between manufacturing processes, and they're why "billet" vs. "forged" is really a spectrum rather than a binary classification.
If one were to simply machine a completely blank billet into a wheel, the grain structure would be whatever was in the billet rather than what would be best for the finished wheel. The result might still be better than a cast or flow-formed wheel, but it wouldn't be optimal.
Additional forging steps can allow more control over the grain structure, potentially bringing it closer to what the finished product needs.
Rays and BBS do more of/with those additional forging steps than many other manufacturers do, which is one reason why their wheels tend to be stronger and/or lighter and/or stiffer (and WAY more expensive) than many other options.
OTOH, brands like Apex use simpler processes to make their forged wheels, which is why those wheels are cheaper than the high-end forged ones while still being better than flow-formed or cast wheels.
"More forged" and "more billet" are crude and slightly flippant ways to make that distinction.