Abstract: A fastening device for establishing a self-adjusting fastening connection between at least two elements. The fastening device includes a frame having at least one opening and a connection to one of the at least two elements. It includes a rod with corrugations, the rod being movable through the at least one opening and it includes a connection to one of the at least two elements and a holding device including at least two locking elements, each locking element including at least one surface including dents/grooves corresponding to the corrugations. The frame or the holding device includes an at least partly tapered shape, and an elastic mechanism forcing the holding device against the frame and thereby the locking elements against each other. A method of establishing a fastening connection between at least two elements with a fastening device is also included.