A method of manufacturing a jointed device of a medical instrument includes providing a machining fixture on a wire electrical discharge machine having an electrical discharge wire. The fixture includes member holes each adapted to accommodate at least one workpiece, the workpiece being adapted to form a portion of the jointed device of the medical instrument. At least two workpieces each include a first workpiece and a second workpiece, accommodated within at least two member holes of the member holes. The fixture is associated with the wire electrical discharge machine so that the electrical discharge wire can cut at most one workpiece at a time. The machining fixture is rotated around a fixture rotation axis at a predetermined angle, which is chosen to provide that the electrical discharge wire can cut only one workpiece at a time. The workpieces are cut by the electrical discharge wire.