The experimental and numerically predicted fatigue strength of steel tire cord filaments used as reinforcing elements in automobile tires has been determined in this study by means of the pure bending test . The filaments had diameters of 0.20 and 0.25 mm and were produced under three distinct conditions of cold drawing strain quantified as 3.37, 3.68, and 3.71 %. All the fatigue tests were conducted at room temperature and at a frequency of 10 Hz via a custom manufactured pure bending tester with a fully reversible alternating strain value, R = epsilon(min)/epsilon(max), is -1. As the drawing strain value increased, the fatigue deformation limit increased parallel to an improvement in the mechanical properties. One can expect that an increase in drawing strain through a decrease in filament diameter will provide an improvement in the light weight design of cars.