B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
B23H—WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
B23H7/00—Processes or apparatus applicable to both electrical discharge machining and electrochemical machining