Soft magnetic materials are very important for magnetic and electric applications. The quality of a material is not only defined by the elements used in the alloy, but also by the internal or external influences like applied stress, which was investigated in this thesis. The material used was M400-50A electrical steel, which corresponds to Fe3\%Si. In this thesis the influence on the hysteresis loops and the magnetostriction on homogeneous deformed ring shaped samples were investigated. For a homogeneous deformation, tensile and rolling procedures were chosen. On the samples, magnetic hysteresis and the magnetostriction was measured. From this measurements the overall core losses, the permeability, the coercive field strength and the magnetostriction were calculated. The observed changes, regarding the deformation, were used to establish a model to predict the losses and magnetostriction at certain deformation. The second part of this thesis investigates inhomogeneous deformation, based on punched ring shaped samples, which were produced by the "Austrian Institute of Technology". Different punching parameters (punching speed, clearance) were applied to simulate a real manufacturing process for cutting electrical steel. Again the changing losses and coercive field strength was analysed. Due to the complexity of the deformation, it can only be predicted using numerical simulations. A similar approach using the Jiles-Atherton model was done in a previous theoretical work. With the measurement data in this thesis, the model can be verified and improved.