There are a lot of ways to perform a job for a desirable outcome. Many of these techniques overlap in capabilities but each has its own specific use-cases as well. Also, they use different press brake tools.
V-bending – The most common metal folding method. The press punch folds the sheet while pushing it into a V-shaped die. The exact method depends on how far the punch presses. These methods are air bending, bottoming and coining.
Air bending is the most widely used, whereas the punch never pushes the metal piece onto the die. Rather, it stops when achieving the necessary angle. Or a little later, to take springback into account.
U-bending – Also uses a punch and a die. Here, the die is in shape of a U. Therefore, it can produce U-channels in one operation only.
Step bending – A way to perform bends with a large radius using a V-die. The punch performs many successive bends. The smoothness depends on the number of steps – the more steps, the smoother the outcome.
Roll bending – This method is for producing a large radius bend without any steps. An excellent way for a smooth final shape when making large cylinders or cones.
Rotary bending – This folding method helps to eliminate the bending marks. Usually, the V-shaped die leaves two lines as marks on the final part. This technique ensures a nice clean finish.