METHOD OF CUTTING OUT PART WITH MAKING PARTIALLY WELDED SPOT IN WIRE-CUT ELECTRICAL DISCHARGE MACHINING

PROBLEM TO BE SOLVED: To provide a method of cutting out a part from a workpiece with making partially welded spots in wire electrical discharge machining to keep the part against falling apart away from the workpiece, breaking the welded spots by an external impact to cut out the part without adding discharge machining, and shortening machining time, thereby improving the machining efficiency.SOLUTION: The method of cutting out a part from a workpiece includes:changing electrical processing condition applied across the wire electrode 5 and the workpiece 6 from a cutting phase to a welding phase at more than one spot of a predetermined contour on the workpiece 6 to fuse partially the wire electrode 5 at the spot; welding together the workpiece 6 and the part 26 cut out from the workpiece with using the fused wire electrode; holding the cut-out part 26 by a welding part 20 using the wire electrode 5 in the workpiece 6; and keeping the cut-out part 26 at the spot against falling away apart from the workpiece 6.