Purpose: This study aims to optimize the surface roughness (Ra) of new-generation WP7V tool steel processed using wire electrical discharge machining (WEDM). The investigation identifies the most significant machining parameters and their effects using Taguchi and response surface methodology (RSM). Design/methodology/approach: WP7V tool steel, a cold work tool steel with low thermal conductivity and excellent toughness, was processed using the Taguchi L18 orthogonal array and optimized through RSM. The input parameters were voltage (4–8 machine units/70–150 V), servo feed (SF) (60–100 mm/min), pulse-on time (Ton) (10–14 µs) and pulse-off time (Toff) (13–18 µs). Ra of the machined surfaces was measured using a Mahr MarSurf PS10 profilometer, and analysis of variance (ANOVA) was performed to determine the contribution of each parameter to Ra. Findings: Ton and Toff were identified as the most critical parameters affecting Ra, contributing approximately 34% each. The optimal combination for achieving minimum Ra was determined as 150 V voltage, 100 mm/min SF, 10 µs Ton and 13 µs Toff. Predicted Ra values from Taguchi and RSM methods were validated against experimental results, showing strong agreement and reliability. Practical implications: The study demonstrates that optimizing WEDM parameters can significantly improve surface quality for new-generation WP7V tool steel. The results provide practical guidelines for engineers and manufacturers to achieve cost-effective, high-precision machining. Originality/value: This work highlights the combined use of Taguchi and RSM methodologies for optimizing Ra in machining advanced WP7V tool steel. The findings enhance the performance and applicability of WEDM for processing new-generation tool steels. Studies on WEDM of WP7V steel are extremely limited in the literature, making this research a valuable contribution to the field.

The basis of the study is to examine the average surface roughness (Ra) value resulting from drilling AA 7075 T6 plates with drills with different point angles () and under different cutting parameters. However, two different point angles (118° and 135°), three different cutting speeds (Vc) (40, 60 and 80 m/min) and three different feeds (f) (0.04, 0.08 and 0.12 mm/rev) were preferred in the experiments. The effect of cutting and tool geometry parameters on Ra was digitized by performing an ANOVA analysis. It was determined that Ra increased with the increase of Vc,  and f. The parameter with the most significant effect on Ra was Vc with 49.10%, followed by  with 30.52% and f with 13.67%, respectively. In order to examine the reasons for the increase in Ra value more effectively, drilling simulations were carried out under different cutting parameters using Deform 3D software. The simulation estimated temperature, cutting force and damage during drilling. The predicted results and the factors on Ra were revealed. In the experiments carried out with the drill with a tip angle of 135°, it was estimated that the temperature, the temperature, the cutting force and the damage value along the Z-axis were higher than the drill with a tip angle of 118°.