Abstract: Riveting apparatus for operation on a workpiece having opposite sides and supported vertically on a horizontal surface comprising a frame having a pair of spaced apart sides movable along the supporting surface and straddling the workpiece, first and second carriages movably mounted on respective sides of the frame and riveting tools on first and second heads on the first and second carriages, respectively, the tools being movable toward and away from the workpiece. The frame travels in a first direction along the supporting surface and along the workpiece, the first and second carriages are movable in a direction substantially perpendicular to the first direction and toward and away from the supporting surface, and the frame is movable in a third direction transverse to the first direction and toward and away from the workpiece.