<b>An Experimental Analysis of Turning Operation in EN 31ALLOY</b> Turning is a form of machining process which is used to create a cylindrical part by cutting away unwanted materials. Today the most common type of automation is computer numerical control, better known as CNC. Components such as axles, shafts can be manufactured by turning process. In that manufacturing unit mainly focuses on high quality with increased production rate and profit level of the firm and so it’s important to determine the optimal machining parameters such as speed, feed and depth of cut. This works deals with the selecting the optimal parameters that plays a critical role in increasing the productivity with desired product quality at minimum cost and reduced lead time. The experiments were conducted with Taguchi’s L 9 mixed orthogonal array. Coated insert was used to machine the EN 31 alloy steel work pieces on computer numerical controlled CNC lathe. The optical parameters were found using Taguchi’s approach individually for minimum surface roughness and maximum material removal rate MRR and were compared with the results obtained from Grey relation analysis. Taguchi, turning, en 31 1498-1502 Issue-2 Volume-2 Sundar.C | Rakesh. V | Ramesh. P | Rajamurthy. G