The 21st century is such an age in which the factories pursue for eco-machining and zero-emission productions, and industrial
productions with minimum side effects on environments. As far as mechanical machining, there exists a status of too much recycling use and emission of
traditional machining fluids which are harmful to operator health and environments in the processes of cutting and grinding, which is in urgent need to be changed. To improve this status, some new types of machining fluids such as dry machining, cooled air, oil mist, water mist and so on, have been
developed and applied recently. These types of machining fluids can improve work conditions, save energy consumption and decrease operation costs. However, their cooling effects are not as good as traditional machining fluids such as emulsion. Obviously, it is necessary to take a strategy for new machining fluids by combination of machining targets and conditions. As a result, this paper developed new machining fluids of oils on water (OoW) to replace traditional machining fluids by mist-jet with cooled air, botanic or ester oils and water. A large number of experiments for physical characteristics and machining performances of OoW machining fluids are carried out on machining-center and NC plane grinder so as to verify oil film forming effects and applicable feasibilities to machining. The investigations show that OoW machining fluids have excellent lubricating effects and good cooling effects, applicable for cutting and grinding.