Bending of sheet metal under bending machine die or mould, under the pressure of the first through the elastic deformation, and then into the plastic deformation, in the initial stage of plastic bending, the plate is bent, freedom as the upper die or mould pressure on sheet metal, sheet metal and die of V type groove surface gradually rely on tight, and radius of curvature and bending arm also gradually become smaller, continue to pressure until the cessation of stroke, lower die and the plate at 3 o 'clock on full contact closely, at this time to complete a v-shaped bending, is commonly known as bending.
Below is the 90 ° V type bending:
