This manuscript reports a study concerning the penetration of eddy currents in metallic non ferromagnetic materials in the presence of linear sub-surface cracks. Simulations were performed for a set of different lengths and depths of the crack using a sinusoidal excitation current with uniform magnetic field distribution. The perturbed magnetic field components (Bx and Bz) that occur due to the presence of cracks were obtained to understand the electromagnetic phenomena involved. The end and center of the crack were analyzed by the magnitude and the complex signature of the obtained magnetic field. The dependence between the length and depth of the crack and both magnetic field components were discussed.