The machining of metal components involves the selection of the cutting material and the cutting tool, including the hard protective coatings on the tool, and the correct selection of the cutting parameters to be adopted on the machine which will be used to carry out the operation. Therefore, for successful production it is necessary to carry out a number of studies for the purpose of optimising the cutting conditions and to thoroughly understanding the tribological conditions at the tool-workpiece interface and the nature and characteristics of the cutting material and hard protective coating. This paper deals with the investigation of the influence of the TiN (PVD) coating on cermet tools on the identification parameters in turning.