Conventional machining processes find it difficult to machine the hard material. The hard material is machined with wire electrical discharge machining (WEDM). The goal of this research is to machine oil hardened non-shrinking steel using WEDM and to decide on the best possible input variables to maximise the machining performance. The experiment was conducted on the EZEECUT NXG CNC Wire Cut EDM using Taguchi’s L27 orthogonal array. The effects of pulse on time, pulse off time, sensitivity, gap, peak current, and wire feed on material removal rate (MRR) and surface roughness (Ra) are observed. An analysis of variance (ANOVA) was conducted to identify the significance of the machining parameters on the material removal rate and surface roughness. The signal-to-noise ratio generates the characteristics that influence the performance and is used to decide the optimum parameter for maximum performance. The investigational results indicate that pulse on time of 35 µs, pulse off time 07 µs, peak current of 3A, sensitivity 9, gap of 15 mm, and feed rate of 4 mm/min yielded optimal values of surface roughness. The best MRR value is obtained with a pulse on time of 25 µs, a pulse off time of 07 µs, a peak current of 4A, a sensitivity of 10, a gap of 10 mm, and a feed rate of 12 mm/min. The confirmatory test is used to validate the effectiveness of the proposed optimal condition. The results of this study show that variables like pulse on time, pulse off time, and peak current have a big impact on how well a machine works.