The best method to estimate the accuracy of the diameter of the parts and the working forces in tube spinning process is discussed. At first, the velocity of the metal and the strain rate in the deformation zone are estimated by introducing the parameters ξ and z₀ obtained from the observation of the previous experiments. The optimum values of ξ which has an effect on the accuracy of the diameter or the parts are obtained by minimizing the deformation energy of the tube consumed on the contact area between the roller and the mandrel. Therefore, the proposed method is useful for selecting the working forces in tube spinning can be obtained with good agreement between the experimental and calculated results by this method by knowing the deformation resistance of specimen and the other working conditions.