The present work deals with, experimental investigations to understand the role of cryogenic treatment, on tool wear mechanism and dimensional variations in machining of crank shaft as a case study. Commercially in machining of crankshaft, tungsten carbide and HSS tools are used. The tool life results have been compared with treated and untreated tools. Cutting conditions like feed, depth of cut and geometry of tools were held constant throughout the experimental study. The method of measuring tool life in this work is in accordance with ISO3685 tool life testing standard for single point turning tool. For HSS tools result indicates that tool life improves by 20%. The best settings of parameters for CNC machine are cutting speed 290m/min for roughing and finishing tool, 280m/min for facing tool. Further the result of study suggests that tool life of tungsten carbide inserts increases by 22%. After the cryogenic treatment of tools, machining cost per component has been reduced by 14.75%.