From DT Online
A Bench Folder (aka Bending Brake) is a machine designed to fold or bend sheet metal..
Features and Uses
Larger Sheet Metal Folders may be floor standing but more commonly used hand-operated sizes are often bolted to the bench top and some smaller versions can be mounted in a Vice. Most Folders are able to bend sheet metal beyond a right angle and usually up to approximately 1200
Box Folders, or Box and Pan folders differ in that the clamping plate is made up of several different width sections which can be arranged to enable folds within the limitations imposed by the width of boxes or trays to be folded.