Microstructure and residual stresses (RS) are important attributes of an industrial material which determines their various properties. In this paper, first an overview is given on the information available on the relationships of the microstructural parameters and RS on one hand and the parameters related to magnetic hysteresis loop and Barkhausen noise on the other The relevance of the relation¬ships for microstructurel characterisations and RS hr magnetic nondestructive evaluation techniques is discussed. Discussion is also made on the development and the use of sensors for the detec¬tion and assessment of magnetic flux to characterise microstruc¬tures. Two case studies on the use of the techniques in industrial materials and components are presented