Machining of hardened steels such as AISI D2 and AISI 304 poses significant challenges due to high hardness, poor thermal conductivity, and rapid tool wear. This research investigates the wear behavior of CVD coated carbide inserts under varying machining parameters such as cutting speed, feed rate, and depth of cut. Taguchi methodology, regression modeling, and finite element analysis (FEA) were applied to optimize tool life, flank wear, and material removal rate (MRR). Experimental, theoretical, and simulation results were compared to identify optimal machining conditions.