The invention relates to a pyromechanical fastening element for connecting two parts in an unremovable fixed mechanical manner. The invention is characterized by the fact that said fastening element comprises a metallic shell (2), within the head portion (3) of which a pyrotechnical propellant charge (4) that borders an adapter (5) is disposed, while a fastening means for a first part (1a) is disposed adjacent to the adapter (5) on the rear portion of the shell (2). A second part (1b) can be slid between the first part (1a) and the adapter (5). The head portion (3) of the shell (2) is provided with set fracture notches (6) which rip the shell (2) open and make said shell (2) bend around the adapter when the propellant charge (4) is ignited, whereby the first part (1a) is connected in a fixed manner to the second part (1b).
