MANDLE BENDING
Mandrel bending as a technique is usually used to process tubes with small radii, usually 3D (the bending radius is 3 times the outer diameter of the tube). The mandrel regulates the plastic flow of the material in the machining area to maintain its shape by performing the bending of the thin-walled tubes. A mandrel is required if the ratio of the pipe diameter to its thickness exceeds 20. Otherwise, bending the pipes with the mandrel is not necessary because the forces in the processing area are not sufficient to cause the pipe to corrugate. It bends steel pipes with a mandrel up to a diameter of 76 [mm].
Using this technique, it can also perform 3d (spatial) bending of pipes when the individual segments are not on the same plane.
The key to the effective use of the mandrel is the proper positioning of its face with respect to the bending point. When bending thin-walled pipes, it is necessary to support the inner surface of the pipe in the bending area (see picture below). This ensures a mapping of the shape of the mandrel face on the vertical cross section of the pipe.
The factor limiting the extension of the mandrel is the point of intersection of its external contour with the external wall of the pipe. It is generally recommended that the face of the spindle (excluding its radius) be placed approximately 2/3 of the distance between the point of intersection and the line of tangency. This allows the cross-section of the tube to be slightly flattened on the outside of the bend radius. This phenomenon inevitably occurs due to bending stresses.

PIPE BENDING WITH A THREE-ROLL BENDER
Bending pipes and profiles using three-rollers is the most cost-effective method of producing parts with different radii. We perform cold bending of pipes with the use of standard equipment with diameters from 60 [mm] to 660 [mm].

ADJUSTABLE BENDING
Our partners have developed a method enabling the bending of thick-walled pipes with large diameters above 660 [mm] for various applications. We can make bends on pipes with a diameter of up to 1524 [mm] with a wall thickness of up to 100 [mm]. The pipe is the strongest closed profile used in structures because all its bending axes are the same. The incremental bender allows to bend steel pipes with a bending strength index up to 84,000 [cm3]. This gives designers the opportunity to use a wide range of profiles optimal for their projects.