A method of cutting, polishing and then welding together two metallic components (10, 18), in which the respective components (10, 18) are cut to define respective cut surfaces (14, 16) that are to be polished and fitted together, both to define the relative positions of the two components (10, 18) to be fixed by the welding and to provide facing weld surfaces at which the two components (10, 18) can be welded together. The method is characterized by the steps of i) making at least one extra cut (20), to create at least one zone of elastic deformation that deforms when the cut surfaces (14, 16) are fitted together; ii) polishing the cut surfaces (14, 16) before fitting them together; and iii) designing the dimensions of the cut components (10, 18) so that the zones of elastic deformation compensate for the variations of dimensions caused by the polishing step, thereby retaining the capability of the polished cut surfaces (14, 16, 20) to define said component (10, 18) relative positions during the welding step.