A comparative evaluation of the calculation results obtained using equations known private moment for the threading cutting oscillator circuit. It is shown that the consideration of a limited number of design parameters of the tool cutting, without cutting geometry and kinematics of the cutting profiles, leads to low convergence calculation results. Shows the vector diagram of the tangential forces acting on the main and auxiliary cutting blade cutting the elementary profile, given the errors of calculating based on assumptions. The analytical form of the dependence of the magnitude of the moment of tapping size of the executive instrument, which allows to determine the behavior of the tangential component of cutting force and cutting the time in forming the threaded surfaces. The results of theoretical and experimental studies on the effect of the entering angle of taps on the dynamics of the process of threading.