A common objective in tube bending is to form a smooth, round bend. Most tubes are cylindrical, but oval, square and rectangular cross sections are also available. Indeed, tube bending is one of the most frequently used fabrication techniques for stainless steels.ģ General parameters used in tube bending Bent tube ensures a continuous, even surface.īent tube can therefore be the easiest and most efficient solution to a design task. The risk of crevice corrosion must also be taken into account.

Depending on the conditions, these may be undesirable because they can trap corrosive substances. In mechanical joints with couplers or flanges, crevices are inevitable.A one-piece design in bent tube avoids these fabrication steps. Mechanical removal is only possible for the outside of the tube. The chemical removal of heat tint employs acid-containing products, usually involving environmental and safety precautions. Shielding gas may be difficult to apply, especially on site. Welded joints, for example between straight tube and elbows, require the prevention or removal of heat tint.2 Ways to achieve curved tubular designsĭesigns using bent tube can be preferable to mechanical or welded connections for a number of reasons: These need not be discussed in detail, therefore, in this publication. Typically the software of computer-controlled machines or the technical documents accompanying manually controlled machines provide reliable information about parameters such as minimum/maximum wall thickness, diameter and bending radius, the necessity of mandrels, overbending, etc. The publication gives a basic understanding of the various processes, providing an overview of the options that may need to be discussed between customer and tube-bender. fabricators planning to sub-contract tube-bending work.The brochure highlights the advantages and practical implications of designs using bent tube. designers who have to choose between different ways of achieving curved tubular parts or assemblies (welded/flanged/bent).

Title photos: Patrick lints, Ghent (B), Condesa Inox, Vitoria/Álava (E), Thomas Pauly, Brussels (B) Contentsģ general parameters used in tube bendingĥ Austenitic – ferritic – duplex: differences in forming behaviour

Square tube bending radius chart