Abstract:The combination of the traditional pipebending technology and the CNC technology of machine tool make the pipe bending process automation. However, there is no fixed size and material specifications. Moreover, the nonlinear relationship between the bending moment and the sizes brings troubles in choosing an electric machine of the CNC pipebending device. Therefore, this paper presents a formula to calculate the pipebending moment, for improving the calculating efficiency and reducing the testing cost. The numerical simulation and experimental test were carried out to verify the accuracy of the formula, respectively. The result shows that the presented formula is effective in solving the engineering problems.