Rullforming

Rullforming, or roll forming, is a continuous metalforming process in which a long strip of metal, commonly coil-fed steel or aluminum, passes through a sequence of roll stands. Each stand partially bends the strip, and through many stands the strip assumes a final cross-section. The profile is produced gradually, so the cross-section remains essentially constant along the length of the part, enabling long, uniform components.

The process typically begins with unwinding the coil, feeding the strip through successive pairs of rolls, and controlling tension and alignment with guides and conveyors. After the final stand, the formed profile may be cut to length and, if required, post-forming operations such as punching, notching, or coating can be added. Roll tooling can be customized to create a wide range of profiles, including channels, angles, C and U sections, and complex flat-based shapes.

Materials used include carbon and stainless steels, aluminum, copper, and other alloys. Roll forming is especially effective for high-volume production of long parts with precise geometry and good surface finish. Common applications span construction (roofing, siding, channels, and purlins), electrical and automotive components, and manufactured framing systems.

Advantages of roll forming include high production speeds, reduced labor costs, and consistent dimensional tolerances over long lengths. It is energy-efficient for large runs and suitable for continuous packaging. Limitations include high initial tooling costs, the requirement for a constant cross-section along the length, and limited flexibility for short runs or highly complex varying profiles. Quality control typically addresses thickness tolerances, flatness, and straightness, with inspection often performed inline or at the cut-off stage.