In micro-electro discharge machining (micro-EDM), electrodes plays important role during machining operation. The tool electrode should possess the desirable properties like easy machinability, low wear rate, good conductor of electricity and heat, cheap and readily available. Present paper deals with comparative investigation of machining characteristics such as MRR, TWR, OC, MT and Taper during microhole drilling in micro EDM on AISI 304 stainless steel material using copper and brass electrodes using de-ionized water as dielectric. Furthermore, surface characteristics and entry and exit diameter of machined microholes have also been investigated through SEM micrographs. Results from a thermal finite element analysis are also presented to show how the thermal action of the micro-EDM process affected the surface integrity of machined workpiece. The results of the thermal finite element analysis show high temperature gradient zones in a machined workpiece. Thermal is performed in this study using the commercial FEM package ANSYS 11.0.
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