This work presents an electromagnetic method for mechanical stress evaluation using a U-shaped eddy current (EC) sensor. This technique exploits the magneto-elastic constitutive laws of ferromagnetic materials. Observing the sensor impedance provides information on both the initial magnetic anisotropy and the stress-induced magnetic anisotropy. Measurements from API-5L X52 steel pipelines in the longitudinal (DL) and transverse (DT) directions are used to validate this methodology.