Metalworking fluid is used to cool and lubricate the work surface. Depending on the type used, it will also contain, in part, components that aid in rust protection, bio-defense, and solution stability. Here’s a breakdown of the types of metalworking fluids and what their constituent components are:

As seen here, all MWF types have components which aid in the extreme pressure generated by the metalworking process, a boundary lubricant to keep molecules slippery, corrosion inhibitors to prevent rust, defoamers to control foam, metal deactivators to deactivate the ions that can degrade the fluid, and a dye for aesthetics.

All but the straight oils contain some type of biocide to control bacteria, pH buffers to keep the pH consistent as possible, and a stability agent to keep the mixture in solution. Oilsolubles and semi-sythetics contain mineral oils as their bases, and incorporate emulsifiers to maintain their emulsions when mixed with water. A full-sythetic contains no oils, but a wetting agent to handle lubricity needs. Each type, however, has its own attributes, and these should be considered when selecting a particular blend for the metalworking operation.

When your fluid starts to fail, tankside additives can be added to control the problem, if necessary. Check with your coolant supplier to find out more information on what additives they recommend to use with your particular coolant blend for each failure type.