The closure element includes a tensioning pin which can be tensioned and a head part of which forms a closure disc that can be spread apart by the tensioning pin. The closure disc is pressed, in the installed state, against an inner wall of the bore to be closed. When a specific tensile stress is reached, the tensioning pin is separated from the closure disc at a predetermined breaking point of the tensioning pin. The easy-to-handle tensioning pin facilitates the installation of the closure in the bore in the component. Since the closure disc is pressed against an outer counterholder during the installation process, it can be inserted into a continuously smooth bore. The limitation of the tensile stress effected by way of the predetermined breaking point also ensures that the bore is closed with a defined closing force.