Abstract: The bending assembly for one or more tubes at a time comprises a matrix or ie with substantially smooth cylindrical skirt and a sliding block provided with a groove for receiving the tubes to be bent and angularly rotatable relative to the matrix or die. The matrix or die and sliding block, along with a bearing shoulder for the tube to be bent, are retractable in a direction at right angles to the bending plane. In addition to the bending assembly, the apparatus comprises clamping devices and also structure for automatic centering of the tube and taking up of the tolerance on the legs or between different bendings. These last mentioned devices are arranged in line in a same structure, the bending and clamping devices being mounted on slides.