Hot machining is a type of cutting operation that an external heat source is used to pre-heat and consequently reduce the yield strength of the workpiece material. In this study, the conventional and hot turning of AISI۶۳۰ hardened stainless steel, which is widely used in energy equipment, aerospace, and petrochemical industries, have been evaluated in both numerical and experimental methods. Simulation of the turning process is carried out by finite elements method (FEM) using AdvantEdge software. To predict chip morphology and cutting forces, the ۲D and ۳D FEM analyses have been used, respectively. The numerical analysis showed that hot turning in ۳۰۰°C causes a reduction of ۲۸% in cutting forces and consequently decreases stressed on the cutting tool. It is found that the main factor affecting the fluctuations of the cutting forces in turning of hardened AISI۶۳۰ is the saw-tooth formation phenomenon (chip segmentation) as well as the shear band generation due to thermal softening of the workpiece material. Furthermore, the relation between cutting force fluctuation and the machined surface roughness has been investigated applying numerical analysis and experimental data. The results of roughness measurement revealed that hot turning in ۳۰۰°C reduces the machined surface roughness up to ۲۳%. In addition, it has been observed that hot turning technique decreases side flow and surface damages in comparison to conventional turning.