Why does olive oil work well as a coolant for titanium machining? Olive oil stops aerospace titanium from literally welding itself to a cutting tool. But it works so well for one surprising reason: it isn't actually a coolant. Titanium has two distinct physical properties that make it a nightmare on a milling machine or a lathe. First, it has exceptionally low thermal conductivity. When you cut a metal like steel or aluminum, the heat generated by friction transfers into the metal chips that fly off the workpiece. When you cut titanium, the heat has nowhere to go. It concentrates almost entirely at the tip of the cutting tool, superheating the edge. Second, titanium is highly chemically reactive at elevated temperatures. As the cutting edge gets hot, the workpiece binds to the tool in a destructive process called galling. Once the metal sticks, the tool's geometry changes, friction skyrockets, and the tool snaps or burns up entirely.