A workpiece-treating machine has a pair of longitudinally extending and transversely spaced upright walls and a plurality of horizontal transverse webs bridging the walls and forming therewith a rigid elongated frame defining at one longitudinal end a receiving station, at an opposite longitudinal end an output station, between the receiving station and output station a pair of longitudinally spaced working stations, and a transfer station between the working stations. A workpiece is introduced into the frame at the receiving station and taken out at the output station. A guide above all the stations carries mounts shiftable along the guides above the stations. Respective grippers shiftable vertically along vertical rails on the mounts can hold the workpieces in the working stations for action by tools therein and carry the workpieces longitudinally from station to station.
