This topic brings together content related to sheet metal technology. Including sheet metal unfolding calculation, sheet metal processing practical manual, sheet metal technology, sheet metal forming technology, etc. Sheet metal, a processing technology, sheet metal has not yet had a relatively complete definition. According to a definition in a foreign professional journal, it can be defined as: sheet metal is a comprehensive cold working process for thin metal plates (usually below 6mm), including cutting, punching / cutting / compositing, folding, riveting, splicing, Molding (such as car body). Its distinctive feature is the same thickness of the same part.