(1) The production efficiency of the radial drilling machine is low. When EDM is used as roughing for forming, although the profiling is good, its cutting efficiency can only be equivalent to an instrument lathe. Therefore, for parts that can be machined by metal cutting methods, EDM is generally not considered.
(2) The workpiece to be processed can only be a conductor.
(3) There is electrode loss. Since the electrode loss usually occurs at the edge of the sharp corner, the forming accuracy is affected. In order to meet the accuracy requirements, the cost of multiple electrodes and the auxiliary time for electrode replacement are often required.
(4) There is a metamorphic layer on the machined surface. Preliminary studies have shown that the surface of the workpiece to be processed generally has a metamorphic layer, such as the metamorphic layer on the surface of stainless steel and cemented carbide, which is harmful to use and needs to be disposed of.
(5) The processing process must be carried out in the working fluid. The discharge part must be in the working fluid during EDM, otherwise it will cause abnormal discharge.