A method of manufacturing a jointed device (70, 170, 270) of a medical instrument (60, 160, 260, 360) comprising the following steps: (A) providing a machining fixture (112) on a wire electrical discharge machine having an electrical discharge wire (115), said machining fixture (112) comprising a plurality of member holes (116) each adapted to accommodate at least one workpiece (117), said workpiece (117) being adapted to form at least one portion of said jointed device (70, 170, 270) of said medical instrument (60, 160, 260, 360)； (B) providing at least two workpieces (117), comprising a first workpiece and a second workpiece, accommodated within at least two member holes (116) of said plurality of member holes (116)； (C) associating said machining fixture (112) to the wire electrical discharge machine so that said electrical discharge wire (115) can cut at most one of said at least two workpieces (117) at time； (D) cutting said at least two workpieces (117) by said electrical discharge wire (115)； (E)rotating the machining fixture (112) around a fixture rotation axis (R-R) of a predetermined fixture rotation angle, said predetermined fixture rotation angle being chosen to provide that said electrical discharge wire (115) can cut at most one of said at least two workpieces (117) at time； (F) cutting said workpieces (117) by said electrical discharge wire.
