Hard materials are widely used in industry due to qualities such as strong fatigue strength and the ability to maintain strength at a high temperature. Still forming certain raw materials into the appropriate shapes is the challenge in subtractive manufacturing industries and these materials are categorized as hard to machine material. To solve this problem Heat Assisted Machining (HAM) is an emerging and most dominating method, which requires an external heat source subjected to the workpiece either before or during the machining to increase the ductility. As a result, the workpiece yield and shear strength are reduced. This is an advanced technique to enhance the tool’s life, and productivity. The present paper provides in-depth knowledge of thermal assisted machining process where various heat sources are used like laser, plasma, LPG, Induction heating and etc. The comparison analysis between various heat sources is made and their impact on various parameters like tool wear, material removal rate, surface roughness, stability and etc. were illustrated and provide the novel approach for selecting the correct heat-assisted technique which is used for turning process in order to increase the machining process.