Which process is used to reduce the thickness of metal?

The process used to reduce the thickness of metal is rolling. During rolling, metal is passed through a pair of rolls, which compresses the material and reduces its thickness while simultaneously increasing its length. This technique is particularly effective for producing sheet steel and other products that require a flat, uniform thickness.

Rolling can be performed at room temperature (cold rolling) or at elevated temperatures (hot rolling), depending on the desired properties of the final product. Cold rolling typically enhances the strength and surface finish of the metal, whereas hot rolling can make it easier to shape the metal without cracking.

In contrast, casting involves pouring molten metal into a mold to create a desired shape and generally does not focus on reducing thickness. Stamping is primarily used to cut or shape metal sheets into specific designs rather than altering their thickness through compression. Forging, while also a process that shapes metal, typically involves deforming the material through localized compression rather than uniformly reducing thickness across a sheet. Therefore, rolling is the clearly defined method for reducing metal thickness.