Evaluation of microcrack formation of ABNT M2 high speed steel in the EDM process, with addition of silicon carbide powder. It is known that Electrical Discharge Machining (EDM) is a thermal process in which extremely high temperatures (in excess of 1200 degrees C) can occur in the machining area. Consequently, it is easy to understand that during each electric discharge, high temperatures are generated, causing local fusion or even evaporation of the machined material. In each discharge, a crater is formed in the material and a small crater is formed in the electrode. Of every melted material produced in each discharge, only 15% or less is removed using dielectric fluid. The remaining melted material solidifies, forming a wrinkled surface. The characteristics of the obtained surface - overlap of craters, globules of sullage, chimneys, bubbles (formed when the gases arrested are liberated through the resolidified material) - are revealed through an analysis using a scanning electron microscope. The proposed work has as its objective to study the effect of the addition of SiC powder into several dielectric fluids, on microcrack formation of high-speed steel (ABNT M2), during electrical discharge machining. The results show that the samples machined with the addition of SiC powders presented significant reduction in the number of microcracks in the machined surface, when compared with those machined with conventional EDM.302173179