In the case of the device for forming or injection-molding elements onto surfaces of a semi-finished product (2), a C-shaped bow element (1) is designed in such a way that it can be moved and can be positioned in a locally defined manner relative to a semi-finished product (2) by means of a manipulator. An assembly (1.4) designed for injection molding is arranged on a first leg (1.1) of the two oppositely arranged legs of a C-shaped bow element (1), and a counter-holder (1.3) is arranged on the second leg (1.2) of the C-shaped bow element (1). A semi-finished product (4) can be arranged between the counter-holder (1.3) and the assembly (1.4). A first mold (1.4.1) having a negative contour of the element in question is arranged toward a surface of the semi-finished product (2). The assembly (1.4) and/or the counter-holder (1.3) can be moved against the particular surface of the semi-finished product (4) such that the open side of the first mold (1.4.1) touches the particular surface of the semi-finished product (2) with compressive force, and the counter-holder (1.3) touches the opposite surface of the semi-finished product (2) with compressive force.