Tech Talk
What are "Water-Soluble Oils"?
These cutting fluids are suspensions of oil in water. These suspensions (also called emulsions) consist of one part oil to, usually, 20 to 25 parts water. They usually include additives which enhance the lubricating properties and which also help to keep the oil in suspension (prevent the oil from floating to the top). Soluable oils have a better surface-wetting action than straight cutting oils, i.e., they don't bead up as much and their surface coverage is more uniform. This wetting action usually improves when rust inhibitors and other commonly-used agents are added. Because of the superior heat transfer characteristics of water, soluble oil cutting fluids are used primarily as coolants. And, as with oil-based cutting fluids, the lubricating properties of soluble oils can be enhanced with polar or EP additives. Soluable oils can be used for most light, medium and heavy-duty milling operations involving steel. They are less effective on the very difficult-to-machine alloys. Soluble oils offer a number of advantages over cutting oils in end milling operations:
(1) Tools run cooler;
(2) Higher milling speeds can be used;
(3) They are cheaper to buy initially, have a longer useful life, and are less costly to dispose of;
(4) There's less odor and mess, so working conditions are more agreeable; and
(5) The water-based fluids do not represent a fire hazard.
