Cold-formed steel is not formed with heat, like most other steels; instead, it is formed with rollers and presses to make it the correct size and shape. This results in cold-formed steel being lighter than other steels, and it tends to have somewhat more elasticity. Unlike hot-formed steel, which is difficult to warp, cold steel is relatively easy for workers to change and bend. This steel is used to make cars, transmission poles and certain buildings.
Most steels are formed under very hot temperatures; the steel is melted, placed in a mold and cooled to form a certain shape. Cold-formed steel starts as plates of steel that are rolled and stamped until the plates are the correct size and shape. The rollers thin out the steel, so it can be easily bent, and the presses add curves and lines so the steel takes on the intended shape, such as an L-shape or curved line. While the process is not entirely cold, because the presses and rollers cause heat by friction and movement, the heat is not enough to melt or deform the steel without additional pressure.
When compared to hot steel, cold-formed steel is much lighter. This is because less steel is generally needed to create a similar shape when cold pressed; this drives down the steel's cost and makes it suitable for lightweight uses. It has somewhat more elasticity than hot steel, as well, typically around 29,500 kilopounds per square inch (ksi), or 14,124 bar, compared to hot steel’s 29,000 ksi (13,885 bar).
Its increased elasticity and the initial deformation from the rollers make it easier to work with, so workers can easily make cold-formed steel into different shapes at a worksite. This allows cold steel to be versatile, because it can be made to fit most needs on the fly. Hot steel comes in a standard shape and is very difficult to warp; while this makes hot steel good for support, it is usually not as good for detailing.
This steel is used in many items that need to be flexible and lightweight. For example, cars that have steel frames need steel that can be easily warped to the body’s shape, and the steel has to be light or the car will be unable to move quickly. Hot steel is typically used for buildings, but smaller buildings can be made from cold-formed steel if the steel does not have to support a massive amount of weight.