综述了走丝电火花加工中金属去除机理的基本原理，提出了走丝电极的功能要求。定义并比较了拉伸强度和断裂韧性特性，以说明断裂韧性在控制电火花线切割事件中的更关键作用。此类断裂是由放电过程引入导线的缺陷造成的，并对促进这些缺陷的操作条件进行了综述。讨论了通过修改机器操作模式来减小缺陷有效尺寸的技术。确定了在给定张力水平下可承受较大缺陷的钢丝类型，并讨论了各种应用中钢丝类型的选择。

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.