Structural shape rolling
Encyclopedia
Structural shape rolling, also known as shape rolling and profile 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, U-beams, angle iron, channels, bar stock, and railroad rails
. The most commonly rolled material is structural steel
, however other include metal
s, plastic
, paper
, and glass
. Common applications include: railroads, bridge
s, roller coaster
s, 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. This process can roll workpieces into full circles.
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.
Bending (metalworking)
Bending is a manufacturing process that produces a V-shape, U-shape, or channel shape along a straight axis in ductile materials, most commonly sheet metal. Commonly used equipment include box and pan brakes, brake presses, and other specialized machine presses...
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, U-beams, angle iron, channels, bar stock, and railroad rails
Rail tracks
The track on a railway or railroad, also known as the permanent way, is the structure consisting of the rails, fasteners, sleepers and ballast , plus the underlying subgrade...
. The most commonly rolled material is structural steel
Structural steel
Structural steel is steel construction material, a profile, formed with a specific shape or cross section and certain standards of chemical composition and mechanical properties...
, however other include metal
Metal
A metal , is an element, compound, or alloy that is a good conductor of both electricity and heat. Metals are usually malleable and shiny, that is they reflect most of incident light...
s, plastic
Plastic
A plastic material is any of a wide range of synthetic or semi-synthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce production costs...
, paper
Paper
Paper is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....
, and glass
Glass
Glass is an amorphous solid material. Glasses are typically brittle and optically transparent.The most familiar type of glass, used for centuries in windows and drinking vessels, is soda-lime glass, composed of about 75% silica plus Na2O, CaO, and several minor additives...
. Common applications include: railroads, bridge
Bridge
A bridge is a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle...
s, roller coaster
Roller coaster
The roller coaster is a popular amusement ride developed for amusement parks and modern theme parks. LaMarcus Adna Thompson patented the first coasters on January 20, 1885...
s, 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. 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
Moment of inertia
In classical mechanics, moment of inertia, also called mass moment of inertia, rotational inertia, polar moment of inertia of mass, or the angular mass, is a measure of an object's resistance to changes to its rotation. It is the inertia of a rotating body with respect to its rotation...
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.