Aim: This experimental investigation compares the performance of Chrome Nitride (CrN) coated WC tool with uncoated HSS tool for CNC green machining in turning the High Strength Steel EN3B for improving surface finish  and material removal rate in green machining method. Materials and Methods: The experimental group high strength steel EN3B material work were machined with Chrome Nitride (CrN) coated tungsten carbide WC tool insert and the same kind of works were machined with uncoated High Speed Steel (HSS) insert tool for control group. Calculated Sample size at G power 80% setting was 16 per group and total 32. Results: The results revealed that the feed rate was the most important parameter affecting the surface roughness and depth of cut affects considerably cutting force and power. The significance Value of p was 0.0275 and which is lesser than 0.05 for surface roughness observations and for material removal rate p = 0.0344 <0.05. Conclusion: The material gives a good material removal rate (Averagely improved 29.22%) and surface roughness (Averagely Reduced  by 56.61%) with use of with Chrome Nitride (CrN) coated tungsten carbide WC tool insert than conventional HSS tool insert in machining the high strength steel EN3B material work.