Abstract: An improved method and apparatus for forming box-shaped sheet metal ducts with Pittsburgh-type seams. The improved method is a continuous process in which the sheet metal is fed from an uncoiler, and after straightening and notching, the leading edge is fed into a single apparatus that performs all of the remaining forming functions. In this single apparatus, the leading edge of the material is formed into the male portion of the Pittsburgh seam, after which the box is formed and then the female portion of the Pittsburgh seam is formed and the material sheared to complete the box section. Using this improved method eliminates the moving of separate parts from one station to another, thereby improving the efficiency of the forming operation and the quality of the resulting box section.