Also called machining coolants, these fluids need to be diluted in water before being applied for lubrication, cooling, and debris removal. They're commonly used in circulating flood systems or mist systems that dispense steady streams of coolant directly to your tool or workpiece.
Soluble oil formulas provide the best lubrication and corrosion resistance but often need maintenance. Semi-synthetic formulas allow for better lubrication than synthetic with less maintenance than soluble oil and are usually low staining. Synthetic formulas give the best cooling and surface finish but are less lubricating.