Shrinker/Stretcher Metal-Shaping Combo reproduces wheel wells, dog legs, trunk corners...almost any metal fabrication requiring a combination curve and angle. Use the shrinker to contract metal for inside curves; use the stretcher to expand metal for outside curves.
The hand-operated metal shrinker stretcher press multiplies your pressure by a factor of 45, creating leverage to work on up to 18-gauge mild steel, 20-gauge stainless, and 16-gauge aluminum. Clamps in your vice or mounts on your bench or pedestal stand.
51437 Shrinker/Stretcher Jaw Set (The original-equipment jaws are of hardened steel to provide years of normal use, but if you work with stainless or a lot of carbon steel, the jaws will tend to wear out and replacement will be necessary.)
Some great product detail and practical videos here: