Abstract: A method and apparatus are disclosed which are useful for fabricating integrally bladed rotors. In particular, the method and apparatus are used to increase the twist of the blades on the rotor from a first degree of twist to a second degree of twist under superplastic forming conditions. The apparatus is constructed and arranged such that the method can be carried out at ambient atmospheric conditions. A key feature of the invention is that the blade twisting dies are present in the blade heating zone only when the dies contact the blade. When the dies are not in contact with the blades, they are at ambient conditions where oxidation is at a minimum.