This article or the following section is not adequately provided with supporting documents ( e.g. individual evidence ). Information without sufficient evidence could be removed soon. Please help Wikipedia by researching the information and including good evidence.
In craftsmanship, envelope is the double of the edge of a sheet metal part by folding or swiveling . The purpose of the envelope is to increase the stiffness of the sheet, especially with thin sheets. In addition, the envelope creates a rounded edge that reduces the risk of injury (cutting) on the otherwise sharp edge, e.g. B. in lockers or drawers.
The envelope is also known as a double or a fold .
