Abstract: A structural component having a twisted profile or cross-section, such as a arge scale wing for a windmill or for a helicopter, has an upper portion and a lower portion intimately bonded to each other along an interface formed by two separation surfaces. A longitudinal axis extends in said interface. The interface is defined by simultaneously twisting or rotating and longitudinally moving a polygonal line (PZ) relative to the longitudinal axis while a central portion of the polygonal line extends perpendicularly to the central axis. The machine tool for machining the separation surfaces has a tool carrier (14), and a carrier support (20) for holding the tool carrier (14) in such a manner that the tool carrier is tiltable about the longitudinal axis of the interface. Simultaneously the carrier support is movable in the direction of the longitudinal axis (A).