Effect of die profile and aluminum circular tube thickness with MOS bending.

A new flexible type of tube bending method, based on the penetration bending, was invented by the author. It has been named the MOS bending method. Using the aforementioned bending method, tubes can be bent to the required bending radii by shifting the relative distance between the die and tube. The bending radius, the flattening of tube cross section and the bending forces are experimentally investigated as functions of the die bearing radius and the tube thickness using the MOS bending method and the results are summarized as follows, (1) The bending radius, flatness and bending forces had no effect on the die bearing radius. (2) The bending limit was extended, as the wall thickness increased. The relationship between the offset and the bending radius had little effect on the thickness. (3) The flatness in the wide direction decreased with increasing wall thickness, whereas the flatness in the radial direction was not affected by the wall thickness. (4) The penetration and bending forces increased, as the wall thickness increased.