In this article we evaluate the possibility of using glass coated magnetic microwires as an alternative to optical fiber devices in structural health monitoring in the railway industry. The effect of applied stress on hysteresis loops of Fe71.80B13.27Si11.02Nb2.99Ni0.92 and Co65.34Si12.00B10.20Cr8.48Fe3.90Mo0.08 microwires has been studied and analyzed. An interpolation function has been obtained relating the coercitivity Hc with the applied stress.