So what is the difference between a FMW and billet? Talking to a friend of a friend and he says...FMW is much better than billet..so I say well looks identical to the billet wheel I had in my Danville72 and I can't physically see how one is "better" than the other.
A billet is a forging...or am I missing something here? Just curious.
It's my understanding that-
Billet and forged are of, or can be made of the same material.
The difference between them is the processing.
Billet is made from a raw chunk of metal, aluminum and steel are what were used to seeing.
It's the end result of a refining process that achieves the "billet" definition.
Something that's called "billet" is something that is cut from one solid "rod" of billet material to make the product, ie a billet wheel/rim, grille, valve covers and even the compressor wheel for a turbo. The process of making the metal billet is what makes it stronger than cast as it's heated into a cylinder then placed into a very powerful hydraulic ram and extruded out into a smaller cylinder known as a billet rod, then it's heat treated or "aged" a couple times and then it's ready to be used for manufacturing.
Forging takes billet a step further, you use a billet stock and heat it up again to something like 450*C (maybe more ICR) and start with a piece that's "bigger" than what's needed. And then actually press or ram/bang the shape of the part out of the hot softened billet metal, pressing it (forging) into it's shape like this compresses it and makes it more dense by further aligning the molecular structure of the metal making it stronger and more resiliant to things like force and heat.
Think of a forged samurai sword, it's heated, banged to shape and size cooled and that process it repeated over and over again till it's perfect. The metal is never cut, it's continually pounded into a smaller shape, making it dense and strong, the heating and cooling make it resiliant.
In the case of the new BW FMW they forge a block and then mill it down into the compressor wheel. So they're using a stronger material, which allows them to make an even more aggressive profile for the compressor wheel and also allows them to make the fins of the wheel thinner, so it's probably lighter as well as much stronger