Automotive companies in highly industrialized regions are currently facing a stronger competitive situation than ever before. With the onset of Industry 4.0, digitalization of the production systems has been a trendsetter. Due to fast changing markets and push for implementing novel materials, the competitiveness relies increasingly on economical and short planning cycles of machining processes. This has increased the application of simulation tools such as the Finite Element Method (FEM) in manufacturing technologies, including machining. In the last decade, various researchers applied FEM to simulate the macro- and micro- geometry of tools. Furthermore, FEM has been implemented to analyze the effect of coating thickness but has been widely limited to 2D-simulations. In future, a 3D-FEM simulation analyzing the effects of coating thickness in machining can significantly shorten the development cycle, as the simulation can be directly implemented for optimization of mass-production processes. This work presents a 3D-finite element model of a turning operation using AlTiN coated tools with two different coating thicknesses of 4 µm and 8 µm. The Finite Element Method (FEM) simulations are conducted in AdvantEdge software. The influence of coating thicknesses on temperature, and forces are simulated in coating and substrate for a hard to machine casted steel alloy, 1.4837D. The experimental temperature is measured with a two-color pyrometer and the forces are measured with a 3-component dynamometer. In the end, simulated results such as forces and temperature are compared to the experimental measurements and the comparison demonstrates a good agreement between them.