Structural shape rolling
Structural shape rolling, also known as shape rolling and profile rolling,[1] is the rolling and roll forming of structural shapes by passing them through a rolling mill to bend or deform the workpiece to a desired shape while maintaining a constant cross-section. Structural shapes that can be made with this metal forming process include: I-beams, H-beams, T-beams, U-beams, angle iron, channels, bar stock, and railroad rails.[1] The most commonly rolled material is structural steel, however other include metals, plastic, paper, and glass. Common applications include: railroads, bridges, roller coasters, art, and architectural applications.
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.[2] 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 flatteners (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.[3]
References
- ^ a b Boljanovic, Vukota (2009). Metal Shaping Processes. New York: Industrial Press. p. 140.
- ^ How We Form Steel to Bend Metal Pipes and Tubing (roll forming)
- ^ http://www.aasteelfab.com/structural_methods.php
Further reading
- Manufacturing Processes & Materials By George F. Schrader, Ahmad K. Elshennawy