Cutting oils reduce erosion and abrasion between tool and material during metal machining, and also enhances tool life, improves surface roughness and machining accuracy. Different cutting oils are chosen depending on equipment, machining process and material condition. Cutting oils are largely divided into either soluble or neat types according to their composition and method of use. Soluble products are once again divided into Emulsion, Semi and Synthetic types, while neat products are divided according to content and type of extreme pressure additives.