Structural shape rolling
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Structural shape rolling is a metal forming process where structural shapes are passed through rollers to bend or deform the workpiece to a desired shape while maintaining a constant cross-section. Structural shapes that can be rolled include: I-beams, H-beams, T-beams, Z-beams, angle iron, channels, pipes and tubing, bar stock, and railroad rails. The most commonly rolled material is structural steel, however other metals, plastic, paper, and glass can be rolled. Common applications include: railroads, bridges, roller coasters, art, and various building applications where a curved wall, roof, or entrance is desired.[citation needed]
It is a cost effective way of bending this kind of material because the process requires less set-up time and uses pre-made dies that are changed out according to the shape and dimension of the workpiece.[1] This process can roll workpieces into full circles.
Process
Structural shape rolling uses profile rolling techniques where the workpiece is passed through a series of rollers (of larger magnitude than that of common rolling devices) that match the workpieces' cross-section. The most common method uses 3 rollers; the bending is controlled by varying the distance between the rollers.
Structural shapes can be rolled in different ways such as the “easy-way”, the “hard-way”, heel in/out, ball in/out, leg in/out, stem in/out, and off axis. The hard-way would be bending the workpiece in the orientation where its moment of inertia is the greatest. The easy-way is bending the workpiece along the axis with the smallest moment of inertia. For example, a piece of angle iron rolled the easy-way would be rolling it along one of its flanges, while the hard-way would be along the angle itself.[2]
References
Further reading
- Manufacturing Processes & Materials By George F. Schrader, Ahmad K. Elshennawy