Numerically controlled electro discharge wire cutting process has increasingly been applied in producing various required profiles of hard and heat treated materials. Rowever,there is little published work concerning the effect of ED wire cutting conditions on surface integrity of the machined components. Knowledge of the nature and quality of the surfaces produced under various ED wire cutting consitions is of considerable industrial importance. The objective of this work is to investigate, in a comperhensive manner, the effects of the wire feed rate, wire diameter, pulse duration, and the effective
acting length on the surface integrity of both high speed and tool steels. The surface region of the machined components is examined using a wide variety of diagnostic techniques. The results of the investigation show that a wide variety of geometrical surface feature!; are generated at varius ED wire cutting conditions. The results also show that a heat affected zone in the surface region is generated that contains variations in hardness and microstructure. The results, in conjunction with those obtained from previous work will lead to a better understanding of the performance of the ED wire cutting and will aid in the production of surface of high integrity.