Hot turning was a relatively new technology for improving the surface roughness and material removal rate of hardened stainless steels. These material are difficult to be turning whether using conventional or unconventional methods and also facing constraint (like low surface quality and low material removal rate) which lead to high costs and decrease productivity. Hot turning was a procedure for turning hardened stainless steels that was distinguished by its heat capabilities. As a result, increasing the operating temperature was one of the variable and available heating strategies that may be used to warm the cutting zone of the work piece, which helps to soften such zones and make the turning operation easier by reducing their hardness and strength. The experiment was carried out on stainless steel rods with a diameter of 30mm. Cutting speed, feed rate, depth of cut, and tool types were all used as process factors. Process parameters also optimized making use of mixed L16 orthogonal arrays were established with different cutting speed (53.694,120.576,157.314,188.4),federate (0.238,0.302,0.416,0.512mm/rev) depth of cut(0.4,0.6,0.8,1.0mm),types of tool(diamond and carbide tool) and grey relational analysis method with a larger better quality characteristics. In order to evaluate the important process parameters, an ANOVA was used. Cutting speed and depth of cut become significant as a result of this study. Cutting speed 157.314m/min, feed rate 0.512mm/rev, depth of cut 1mm, and tool type’s diamond tool were determined using an ANOVA analysis. The heating techniques are oxy-acetylene gas and heating temperature are control by MLX90614 temperature sensor with Arduino. The findings of five confirmatory tests show that the average values of the grey relational grade are within the 95% confidence interval for the experiment is 0.637, which is in range of the 95 confidence interval and achieved surface roughness and material removal rate of 5.731 µm and 80.540cm 3 /mm respectively. As a result, the confirmatory experiment tests show that this is the safest experiment. Keyword: AISI316; hot machining; surface roughness; orthogonal array; ANOVA; Grey relational; Multi-objective.