Abstract: The capabilities of analytic models in predicting the experimental critical displacements of theself-loosening of bolted-joints were investigated experimentally and numerically. Theexperimental loosening rates were determined in a Junker test bench at a constant transversedisplacement amplitude (0.45 mm) and under varying initial clamp force and clamp length andcontrolled bearing and thread friction coefficients. The analytic critical displacements werethen calculated using experimental parameters. In addition, a three-dimensional accompanyingfinite element (FE) model was developed in order to calculate the ratio of spring constantsengaging the thread to spring. The results showed relatively low capabilities of present analyticmodel in the prediction of the critical displacements of the self-loosening of bolted-joints. Theefforts to modify the nut reaction moment and the inclination compliance of bolt head portionin the investigated equations however resulted moderate increase in the appropriate predictions.On the other side, the use of the reaction moment determined by FE model increased theappropriate prediction from 58.3 to 73.4%. The accuracy of the equations was further increasedby the use of an appropriate kw value, but the increase in this case was only ~4%.