In this paper, experimental investigations on tool wear have been made to facilitate increasing the tool life by sub-zero treatment of carbide insert tool. The effect of computer numerical control (CNC) inserts during orthogonal machining of AISI4340/EN 24 steel, cutting parameters are originated, and the tool life is predictable and compared with untreated and sub-zero treated insert. Generally, the inserts are treated under sub-zero temperature treatment as there is an increase in tool life. Turning parameters such as depth of cut, feed and speed are considered to analyze tool wear. Micro-hardness measurements have been carried out to identify the hardness of treated and untreated insert. Equations are developed using Buckingham’s π theorem, and the results have been validated against experiments. For further implementation, manufacturing with respect to the tool life optimization is discussed.