Abstract: A joining system for mechanically joining two materials is disclosed. A receiving device having a sleeve which surrounds an axis of extension and which is designed to receive a pin, and a plug-in device having the pin, where the joining system is configured such that, when the pin is inserted in the sleeve, the pin is clamped to the sleeve in the axial direction in relation to the axis of extension on account of a spring element of the receiving device being pushed radially against a belly region of the pin.