Sheet metal flattening is a fundamental process in sheet metal fabrication that serves to transform curved or formed sheet metal into a smooth surface by eliminating wrinkles, distortions and residual stresses in its material composition. Manual tools like hammers, mallets and rollers may be used, while automated machinery like press brakes or rolling machines may also be utilized depending on the complexity and desired precision of the part as well as available resources. The choice of method will depend on these factors as well. Flattening sheet metal requires using controlled and gradual pressure in order to prevent further distortion or damage to its sheet metal surface. The process also may include measuring and verifying its flatness using tools like straightedges or optical devices, so as not to distort its integrity further. Sheet metal flattening is essential in achieving dimensional accuracy, assuring proper fit of components during assembly, and streamlining subsequent processes such as cutting welding or forming processes.