(a) a dual head assembly having a lower head and an upper head wherein each head includes a platen for receiving a duct and an assembly for automatically inserting an angle plate into the duct flange; and

(b) a seam closing assembly for automatically closing a seam of the duct comprising (1) a first bender at the lower head and a second bender at the upper head, the first and second benders adapted to first close the top and bottom portions of the seam; and (2) a carriage assembly comprising a pair of vertical support members constructed and arranged outside of the work area of the assembly for automatically inserting an angle plate, a seam closing carriage connected to the vertical support members and having a seam forming member, means for moving the seam closing carriage up and down the vertical support members, the seaming assembly adapted to close the remaining portion of the seam; wherein when a duct is positioned in the apparatus, the assembly for automatically inserting an angle plate will automatically insert an angle plate in the duct flange and the seam closing assembly will automatically close the duct seam.