Sheet Metal Bending

Custom Precision CNC Sheet Metal Bending Manufacturing Process

There are different kinds of sheet metal bending processes used to achieve different bends in different ways. Three of the bending processes (air bending, priming, and embossing) use a press brake, while the others use a variety of machinery.

1. Sheet Metal Air bending

Air bending is a bending method in which a punch presses a sheet of metal into a die, but not so far that it touches the walls of the die.

This method is not as accurate as other methods, but it is very flexible: it can be used to make V, U and other shapes of bends. This is partly because the die geometry does not need to correspond exactly to the desired sheet metal bend because there is no contact between the two surfaces.

2. Sheet Metal Priming Bending

Priming is another bending method. During priming, the punch presses the sheet metal completely into the die, forming a bend that corresponds to the internal geometry of the die. It is used to make V-shaped bends.

3. Sheet Metal Stamping Bending

Stamping is a more expensive type of bending in which the punch is lowered with greater force in the sheet metal and die, creating permanent deformation with little springback.

4. Sheet Metal Folding Bending

Folding can be done on machines such as cornice brakes or pole folders. Clamps the sheet metal in place before the clamping beam is raised to bend the metal around the profile. Folding achieves a V-shaped bend and allows positive or negative bend angles.

5. Sheet Metal Wipe Bending

Wiping Bending (or edge bending or wipe bending) is another bending method suitable for machinery such as cornice brakes and rebar folding machines (and in some cases bending machines). It is faster than folding, but causes more damage to the sheet metal surface.

6. Sheet Metal Roll bending

Roll bending is perhaps the most unique sheet metal bending process due to the machinery used. Roll-bending systems have three cylindrical rollers that bend sheet metal into arcs and are therefore used for the manufacture of pipes, tubes and other round parts.

7. Sheet Metal Step bending

Step bending (sometimes called bump bending) is a method of using a press brake to approximate a smooth curved bend, such as that produced by roll bending. By performing several small V-shaped bends in succession, step bends can create bends that look like bends.

Critical points of bending processing of sheet metal U-shaped parts

1. A standard straight knife die is selected for the upper die, and the groove width of the lower die is selected according to 6 times the plate thickness of the standard calculation method. Without special process requirements, the die width cannot be changed for bending processing.

2. Carefully measure the size of the sheet before bending. If there is a size error, it must be adjusted by adjusting the programming size parameters to ensure important dimensional accuracy.

3. The strip sheet will have different degrees of lateral bending, which must be corrected before bending, otherwise processing is not allowed.

4. Usually, after processing a bending edge, the part will also appear sideways, and it needs to be corrected before the next bending.

5. In order to prevent the parts from deforming, the middle size of the parts should be used as the positioning size for the second bending, and the first bending should be bent against the stop ruler.

6. In order to ensure that the flanges at both ends have the same size, it can be folded at a large angle first, and then reversed for secondary processing.