What is metal shrinking?

• A. Reducing stretched metal back to its original shape
• B. Increasing stretched metal back to an oversized form
• C. Cutting away stretched metal
• D. Heating metal to remove its shape

Answer: (A)

Metal shrinking is the process of reducing the length of metal that has been stretched during forming in order to bring a panel back toward its original shape. When a panel is shaped or bent, the outer surface fibers are stretched and want to be longer. Shrinking uses targeted hammering techniques and backing supports to compress and tighten that area, effectively reversing the elongation and restoring the contour toward the intended dimensions. It’s a controlled way to reduce the arc length of a stretched region so the panel lies flush with adjacent areas.

This is different from increasing the stretched area, which would make it larger; from cutting away material, which removes metal rather than changing its shape; or from heating to remove the shape, which changes hardness and form but isn’t the same as the shrinking process used to correct stretch.