Abstract—The numerical modelling, simulation and experimentation of dry joints steel shear key, used for joining segmental precast concrete girders are studied in this paper. In an effort to identify an optimum shape of steel shear key the numerical study in this paper investigates the response of three different geometries of full scale medium strength steel shear key, including the original shape of shear key, to shearing force at the concrete members and prestressing force acting in the centreline of the shear key. Nonlinear finite element analysis of the shear key and the adjoining concrete members are conducted using ANSYS academic package. The appropriate constitutive relations for the steel and concrete materials obtained from test results and published values in the literature are introduced to the package. The validity of the numerical modelling of the original shear key is compared to laboratory experimentation results of the original shear key. The study considers three different magnitudes of prestressing force with the same concrete compressive strength. Numerical results indicate that introducing a taper onto the forward ring plate of the male part of the steel shear key results in a significant increase in its load-bearing capacity.