Free bending with a universal bending machine


In free bending, the flat workpiece is loosely inserted into a bending device, usually with a die. By varying the depth of the punch, different angles can be bent without changing the tool. Free bending is also known as air bending, free bending and free bending in the die.

Physical laws

Physically, the workpiece fibers are stretched on the outside during free bending and compressed on the inside. There is an unbelted fiber layer that remains unbent and therefore identical in length. The length calculation must be based on this unbent, neutral fiber. The resulting material lengths after the bending can be found in the Europa-Tabellenbuch metal.

If sheets are to be bent, the bends must be transverse to the rolling process. For bends that are at right angles or at different angles, the rolling pattern should be diagonal to the bending edges. For free bending, depending on the material, overbending must be used to compensate for the springback effect.

Free bending with universal bending machine

  • Bending workpieces such as sheets
  • Windows software
  • Universal bending machine with bending punch and die

1. Insert bending punch and die

First of all you have to select in the universal bending machine the bending punch suitable for your workpiece, also known as the bending stroke, and the die, and insert according to the operating instructions.

2. Program software

Bending machines are operated with Windows-based software. Higher-quality bending machines are controlled by CNC, for the operation and setting you need experience. Simpler bending machines have self-explanatory, intuitively controllable, graphical interfaces.

3. Enter values

According to your intended free bending process, you must enter the design data and calculation values.

4. Insert workpiece

When you insert the workpiece into the bending machine, it is symbolically displayed on the operation screen. Align it to display.

5. Corrections

The universal bending machine alerts you to programming errors. If necessary, correct the entered values ​​or design data.

6. Trigger the bending process

Start the bending process in accordance with the machine instruction by pressing a button.

7. Possible parts replacement

For multiple free bending of a workpiece, you may need to replace the punch or die. If the distance between two bends is too short, deactivate the angle measurement function and work with the stroke depth of the punch.

Tips & Tricks

Universal bending machines are designed for the free bending of flat workpieces such as sheet metal. If you want to bend pipes freely, you can use purely mechanical bending machines.


Video Board: My bar bender.. ( simple manual bending setup)