ELEMENTS OF THE METAL REMOVAL MECHANISM IN TRAVELING WIRE EDM ARE REVIEWED TO DEVELOP THE FUNCTIONAL REQUIREMENTS OF WIRE ELECTRODES. TENSILE STRENGTH AND FRACTURE TOUGHNESS PROPERTIES ARE DEFINED AND COMPARED TO ILLUSTRATE THE MORE CRITICAL ROLE OF FRACTURE TOUGHNESS IN THE EVENTS CONTROLLING EDM WIRE BREAKS. SUCH BREAKS ARE SHOWN TO RESULT FROM FLAWS INTRODUCED INTO THE WIRE BY THE DISCHARGE PROCESS AND OPERATING CONDITIONS WHICH PROMOTE THEM ARE REVIEWED. TECHNIQUES FOR REDUCING THE EFFECTIVE SIZE OF FLAWS BEING INTRODUCED BY MODIFYING THE MODE OF MACHINE OPERATION ARE DISCUSSED. WIRE TYPES THAT WILL TOLERATE LARGER FLAWS AT A GIVEN TENSION LEVEL ARE IDENTIFIED AND THE SELECTION OF WIRE TYPES FOR VARIOUS APPLICATIONS IS DISCUSSED.
