The present study is focusing on the experimental and numerical evaluation of the effectiveness of an antiseismic steel device. The developed device, mentioned as CAR1, belongs to the passive energy dissipation systems, as it does not require external power to generate system control forces. It can be used on new or existing structures and can be easily adapted to the particular demands of these. It can be installed in a variety of configurations such as in single or X diagonal bracing in building frames. Moreover the use of this device may result in improving (i) the increase of stiffness,(ii) the absorption of seismic energy,(iii) as well as a control of the axial forces that are developed in the diagonal steel braces. The main part of CAR1 is the groups of superimposed blades, which absorb seismic energy through simultaneous friction and yield. The number and the dimensions of these blades, their elastoplastic properties as well as the friction coefficient over their interface, define the equivalent nonlinear constitutive law of the diagonal bars as a function of their axial force. A Full scale CAR1 device was experimentally investigated under cyclic loading. The experimental load cases were conducted at the Laboratory of Experimental Strength of Materials and Structures of Aristotle University of Thessaloniki. The experimental sets are based on the investigation of the thickness, the cross-section and material of the blades, under different scenarios of cyclic loading with either constant or increasing load. In addition, as far as the numerical study is concerned, Finite Element Models of CAR1 device were developed and analyzed using ABAQUS software, thereby evaluating the reliable performance of the device. In order to simulate the behaviour of the group of the blades in ABAQUS, an explicit dynamic analysis was chosen, on the basis that this type of analysis allows for the definition of-general contact conditions encountered in complicated contact problems, without generating numerical difficulties. After completion of the experiments, the numerical results were compared with the respective experimental ones. Good agreement was shown and further useful results were observed.