Mechanical spectroscopy measurements were performed in commercial grain oriented silicon steel to study the outstanding features of modulus and damping spectrum. A relation between the features of the damping and modulus behaviour with the grain boundaries characteristics will be established. It should be pointed out that the elastic modulus shows an anomalous step at around 800 K. The physical mechanism involved in this process will be studied. A cooperative mechanism involving dislocations will be proposed. Besides this, the magnetic characterization of the samples also will be determined.