Mandrel tube bending of steel is a method for bending square, rectangular, and round tubing as well as pipe. As with any method of bending steel, mandrel bending, which is typically done on a rotary draw bender, has its strengths and limitations.
The benefits of rotary draw bending with an internal mandrel (to keep the steel section from collapsing) include the ability to create smooth bends, complicated bends (bends with multiple radii in two planes, for example), and tight bends (as severe as having a center line radius equal to the outside diameter of the pipe—a 1 x D bend.)
The limitations of such bending include the necessity for tooling to match not only the profile of the member to be bent but also the radius to be achieved. Such tooling can be expensive. Rotary draw bending is also typically limited to 180 degree bends. Lastly, because of the tooling involved, this method is not usually used to bend pipe larger than 10 inch outside diameter (and comparable tubing sizes) or to bend steel sections to radii larger than 3 feet.
The parts produced by steel tube bending and pipe bending are often used as component s of machinery and equipment or in miscellaneous metal construction applications.
