(57) Contoured shapes, especially elongated saddle-section shapes such as helicopter rotor blade erosion shields, are formed from a sheet metal workpiece by providing the workpiece with lateral flange portions that are engaged with respective lateral tools movable in synchronism adjacent to the flanks of an elongate male tool so as to draw the workpiece, by its flange portions, over the male tool and into contiguity therewith. The lateral tools may cooperate with gripper means to grip the flange portions and facilitate stretch-forming. Apparatus for performing this method is also disclosed.