This paper studies the cutting off forces of springs including the introduction of the forming principle of springs and the developments of cutting systems used in spring machines. The shear stresses of various cutting types are simulated using finite element analysis (FEA) for evaluating the cutting forces. The geometric models of the cutting systems are constructed for progressive stress analysis and evaluating the needed forces of the springs cut off. The studied results show that the cutting forces of rotary cuts are smaller than those of straight cuts. The trend of the cutting forces with respect to materials strengths and wire diameters are derived to give a rapid estimation of energy consumption on spring cut offs. The errors of the cutting forces evaluated by FEA and formulations are quite small indicating that the rated methods are feasible.