The invention relates to a thread-cutting screw (1) which is used to screw into a wall (1a) of a borehole (1b). Said thread-cutting screw comprises an essentially cylindrical core (2) which is metal and which has a longitudinal centre axis (4), a thread (5) embodied as a single-piece with the core (2) and at least one cutting element (6, 7) which is arranged in the thread (5) for cutting operations in the borehole wall. The core (2) is made of a metal having a carbon content of between 0 and 0.5 wt.- %. The at least one cutting part (6, 7) is securely connected to the core (2) and is embodied as a welded body made of metal having a carbon content which is greater than 0.8 wt. %. The cutting part (6, 7) ensures efficient cutting with a secure connection to the core (2) and the danger of a brittle fracture to the screw (1) is totally avoided.