A metal shrinker stretcher is a machine that sits in a vertical or horizontal position and compresses metal to create inside or outside curves. They are commonly used in automotive and framing industries, where shrink vs stretch comes into play.
A metal shrinker stretcher is a powerful tool, which can be used to shape any type of metal. To be precise, metal shrinker/stretcher set can expand and contract the size of metals without fracturing them permanently like other tools may do. In auto body restoration work at least for now it has proven more effective than traditional methods such as planishing hammers that have been in use so far because with shrinking process there are no limits on how much one needs to hammer away before achieving desired result while using a planisher hammer you need to hit continuously until finally formulating your required shape.