Temperatures of the carbide tip's surface when turning Carbon-Fiber-Reinforced Plastics (CFRP) composites with a sharp worn main cutting edge tool is investigated. The frictional forces and heat generated in the basic cutting tools are calculated by using the measured cutting forces and the theoretical cutting analysis. The heat partition factor between the tip and chip is solved by using the inverse heat transfer analysis, which utilizes temperature on the carbide tip’s surface measured by infrared as the input. The tip’s surface temperature is determined by finite element analysis (FEA) and compared with temperatures obtained from experimental measurements. Good agreement demonstrates the accuracy of the proposed model.