Abstract: A metal preform is flow formed into a desired structure utilizing segmented dyes. The metal preform is positioned in a chamber comprised of shaping members which define a surface substantially complementary to the desired structure. At least two of the shaping members are spaced from one another and define a groove therebetween. The preform is heated to a temperature suitable for superplastic forming and then compressed such that the preform deforms against the shaping members and into the groove. The at least two spaced shaping members are forced to move into contiguous relationship thereby reducing the size of the groove while forcing further deformation of the preform into the groove.