Cast products have a long tradition. In the early aircraft era, forged products contributed to the domestic manufacture of metal propellers and engine blocks. Traditional forging techniques have been augmented with state-of-the-art technologies to enable the forging of large workpieces and rings, and the development of new alloys to meet increasingly sophisticated needs. Forged product ratings have also increased, and forging methods are changing from conventional mold forging to precision forging using the plamostar molding method, enabling the forging of high-quality impellers and other products.