In simple terms, roll forming is a matter of shaping material using localized deformation with a large amount of material movement. Localized deformation is a permanent bend with a slight thickness reduction at the bending line. Material movement is a matter of relocating or rotating a section, either formed or unformed, without changing its shape. Although roll forming engineers often address these processes at the same time, it can be helpful to consider formation and movement separately.
Figure 1
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The flower diagram for a formed box shows two distinct forming actions: rotation and horizontal movement.
