<p>In this study, CuCrZr, CuNi₂SiCr and CuBe₂ electrodes with three levels of discharge current (<i>I</i>_<i>p</i>), pulse on time (<i>T</i>_<i>on</i>), and pulse off time (<i>T</i>_<i>off</i>) were used for the experimental evaluation of surface crack density (SCD) and white layer thickness (WLT) after electrical discharge machining (EDM) operation of X45NiCrMo4 tool steel. Images from a scanning electron microscope were used to examine the machined SCD and WLT. A grey relational analysis was used to determine the ideal levels of machining parameters for SCD and WLT. As a result of the experimental investigation, the effect of electrode type was found to be limited. SCD increased at low discharge current levels; however, an increase in discharge current yields a greater WLT. The most important parameter at the GRG level is the <i>T</i>_<i>on</i>. <i>T</i>_<i>off</i>, electrode type, and <i>I</i>_<i>p</i> followed in order. The optimization process for SCD and WLT using Taguchi-based grey relational analysis resulted in a 14.25% improvement.</p>