RollForming, also spelled rollforming, is a continuous bending operation in which a long strip of metal (typically coiled steel) is passed through consecutive sets of rolls, or stands, each performing only an incremental part of the bend, until the desired cross-section profile is obtained. RollForming Machinery is ideal for producing parts with long lengths or in large quantities. A variety of cross-section profiles can be produced, but each profile requires a carefully crafted set of roll tools. Design of the rolls starts with a flower pattern, which is the sequence of profile cross-sections, one for each stand of rolls. The roll contours are then derived from the profile contours.
Because of the high cost of the roll sets, simulation is often used to validate the designed rolls and optimize the forming process to minimize the number of stands and material stresses in the final product. Roll formed sections have an advantage over extrusions of a similar shapes. Roll formed parts are generally much lighter and stronger, having been work hardened in a cold state. Another advantage is that the part can be made having a finish or already painted.