Pipe bending

Cold bending is currently the most common means of tube bending for serial production. This process is based on drawing the tube through a hollowed-out lead cam. A pulling stem is used as a lever, which has the equivalent hollowed profile. The stem and the cam combine to form a tunnel, which prevents the tube from being flattened in the bending zone. If you want the profile form to be unchanged in the bending zone, you can also use a mandrel which is specifically adapted to the tube’s inner diameter.

In comparison with alternative production methods, such as cutting and joining tube components, for example, tube bending is a rational, cost effective option.

Bendex normally bends material with:

  • Fixed radii:Traditional bending towards a fixed radius disk.
  • Free radiiThe tube is formed by rolling between movable sections, which is suitable for large, sweeping radii.
  • Variable radii:Some products may require different radii for the same component – in this case it is rational to use this technique with a free radius, enabling the radius of the tube to be constantly adjusted in the same bending cycle.

Bendex provides bending of circular tubing, square tubing and elliptical tubing.

An old rule of thumb is never to bend the tubing less than twice the outer diameter of the tube. However, with modern technology and today’s production demands, we are known to ignore the received wisdom. Modern machines are often equipped with a booster function which enables you to nudge the tube a little extra during forming. This prevents the tube from cracking or deforming, enabling bending at narrow radii.

Besides machine capacity, the condition of the tubing is a key factor. It is vital to choose tube material with the right construction – for example, elongation values.

Bendex AB supplies comprehensive bent and processed structures.