This specialized process begins with a low pressure type of casting and uses a special machine that spins the initial casting, heats the outer portion of the casting and then uses steel rollers pressed against the rim area to pull the rim to its final width and shape. The combination of the heat, pressure and spinning create a rim area with the strength similar to a forged wheel. During Flow Forming, the pressure applied to the cast rim actually changes its mechanical properties, so its strength and impact values become similar to those of a forged rim. That translates to up to 15% less weight when compared to a standard cast wheel. The resulting grain structure within the alloy of the wheel is linear, flowing in a single direction.
This grain structure pattern, combined with the exceptional quality of casting required for the process, gives the rim area of the wheel huge mechanical strength, and elongation. As a result of these mechanical characteristics, Forgestar is able to reduce the thickness of the rim area resulting in reduced weight, without compromising strength and resistance to impact.