The overall experiment result showed that the surface finish. cutting forces, and tool wear are related to the heat generated at the cutting zone and the friction between tool and work surface. Water-based emulsion is the best coolant compare with synthetic oil and compressed cold air. Conventional coolants can be applied in machining of hardened steel while compressed cold air can be used in machining of softer metal like aluminum, mild steel and etc. The effect of different coolants condition to the surface roughness, cutting force, and tool wear has been evaluated. A better coolant and optimal parameters have been figured out.