EN 31 tool steel material is through hardened material that provides good machinability and strength and provides better heat resistance properties. It also exhibits several characteristics, including great shock resistance, high strength, high toughness, and high wear resistance. The present study investigates the impact of three important influencing machining factors on cutting temperature, surface roughness, and main cutting forces and finding of optimum parameters by using response surface methodology (RSM). During machining of hard EN 31 tool steel the eco-friendly cutting fluid (soybean oil) was used, under minimum quantity lubricant (MQL) condition using coated carbide tool (TNMG16040855, SK 15 grade insert). The following factors have been taken into consideration: cutting speed, feed rate, and depth of cut. The regression-based model was developed to find the relationship between the input process parameters and output responses. Through ANOVA analysis it was found the depth of cut followed by cutting speed was found to be dominant parameters for all the three output responses. Further multi-response optimization was done through desirability approach of response surface methodology (RSM) and the optimum values of input parameters were found to be cutting speed = 50 mm/min., feed rate 0.1 mm and depth of cut 0.25 mm.