In air bending, the punch presses the workpiece into the die without pressing it against the walls. While the punch travels downward the legs of the workpiece bend upward and the angle is created. The deeper the punch presses the workpiece into the matrix, the more acute is the angle. A free space remains between the punch and the die. Air bending is called a pathway-dependent procedure. Each angle requires a definite path. The machine control calculates this path and at the same time, the appropriate pressure. Path and pressure depend on the tools as well as the material and product properties (angle, length).

In coining, the punch presses the workpiece entirely into the die, so that there is no free space between die, workpiece and punch. This procedure is called form fit. Punch and die must fit into each other exactly. For this reason, a separate set of tools is required for each angle and each shape. When the workpiece is completely pressed in, the punch cannot move further down. However, the machine control increases the pressure until the predefined value has been reached. This increases the pressure on the workpiece, which then takes on the shape of the punch and the die. Under the high pressure, the angle is stabilized, so that spring-back is almost completely eliminated.

Sheet edges are often bent over completely, like the edges of boxes. The bent legs are then parallel to each other. This either makes the finished part more stable or creates an edge protector. Folds are often needed so that later, another part can be hooked into them. Folding and squeezing occurs in two steps: n the first step, the operator bends a forward angle of 30 degrees. Then he replaces the workpiece and squeezes the angle shut. The procedure is called folding if a space remains between the legs of the bend. In the squeezing process, the legs of the bend are pressed completely together. Folding is path- dependent. Squeezing, on the other hand, is force-dependent.