In the present study, the cooling performance of the Ranque-Hilsch Vortex tube (RHVT) was experimentally investigated by infrared thermography (IRT) method. For this purpose, experiments were conducted on the cutting tool nose point of the lathe at different diameters, cutting speeds and cutting depths for cases in which cooling was not performed and RHTV cooling was performed. The sample material was gray cast iron in the form of round bars with 15 mm and 20 mm diameter respectively and 100 mm length. The inserts were manufactured by Sandvik Inc., with the ISO designation of TNMG 160404 MF (Triangular insert). The inserts were rigidly mounted on three different right hand style tool holders designated by ISO as MTJNR-L2020 K16T. In all instances, the side rake angle and back rake angle are 0 degrees and fixed. The performance of RHVT was determined by using the temperatures obtained from thermal images (TIs). Tls were taken from the FLIR E45 infrared camera at 30 frames per second. When all the experimental results were evaluated together, the maximum performance of RHVT was found to be for a diameter of sample = 15 mm; cutting depth = 3 mm; cutting speed = 800 rpm (P-15,P-3,P-800). (c) 2010 Elsevier Ltd and IIR. All rights reserved.