Due to environmental effects of the wide use of soluble, synthetic and semi synthetic cutting fluids and the hazard involved in the use of these class of cutting fluid, it has become necessary to find alternative cutting fluid for machining operation. The use of biodegradable oils has yielded positive result as they are environmentally friendly and causes no hazard to machinists. Taguchi DOE L9 (33 ) orthogonal array was used in this work to design the experiment and ANOVA was used to analyze the result of formulated Neem oil and Tamarind oil Cutting fluid. The investigation comprised of Three (3) experimental groupings of nine (9) experimental run of Neem, Tamarind and Mineral cutting fluid turned mild Steels. The result clearly indicated that Tamarind seed oil had the best surface quality when used as cutting fluid and the smallest was Mineral oil-based cutting fluid. The minimum surface roughness was 3.142 for Tamarind, 3.842 for Neem and 5.46 for Mineral oil. The optimum cutting parameters for the turning of mild steel was Spindle speed of 1700 rpm, Feed rate of 0.2mm/min and Depth of cut of 0.5 mm. The investigation from the contour plot reveals thatrise in the Spindle speed decreases the surface roughness of the mild steel. The temperature measurement of the cutting zone reveals that experiment 4 had a cutting zone temperature of 36oC, Neem cutting fluid had 39oC, Mineral cutting fluid had 39oC and dry machining temperature was 49oC; Tamarind cutting oil had percentage temperature reduction for the fourth experiment run of 26.53%, Neem and Mineral cutting fluid had the same percentage temperature reduction of 20.41%. Similar pattern was noticed for experiment run 8 where Tamarind had cutting zone temperature of 31oC, Neem cutting fluid 33oC, Mineral oil had cutting zone temperature of 33oC and Dry machining cutting zone temperature was at 40oC; The percentage temperature reduction rate was 22.5% for Tamarind cutting fluid, 17.5% for Neem and mineral oil cutting fluid. The two cutting fluids from the investigation can serve as a good alternative to mineral base cutting fluid.

Keywords : Cutting fluid, Taguchi DOE, Surface quality, Tamarind seed oil and Neem seed oil cutting.