It may not be a standard piece of farm workshop equipment, but for anyone who needs to do a little metal fabrication occasionally, a shrinker-stretcher can be a pretty useful tool. It came in very handy on the Grainews workshop toolbox project.
The metal shrinker-stretcher basically does exactly what its name implies: shrink or stretch metal. It does this with two sets of jaws. As each one clamps down it also either compresses the metal or pulls it apart, which creates the shrinking or stretching action. In this way, the tool actually changes the thickness of the steel, which makes part of the piece longer or shorter depending on which jaw set is used. The dimensions of the unworked section remain the same, so the lengthened or shortened sections created by the tool cause the metal to deform into a curved shape. It’s useful for creating curved corner pieces of sheet metal.
The pictures demonstrate what the shrinker-stretcher does to a flat piece of steel with a single 90-degree bend in it. By using the “stretch” jaws, the outside of the flange is lengthened, creating a curved shape. Using the shrinker side of the tool would cause the metal to “shrink,” forming an arc in the opposite direction.