![](https://freesprung.net/resources/uploads/2021/01/cut-stresses-with-stearic-acid-applied.jpg)
How Sharpie Markers Improve Metal Cutting Performance
Ductile metals pose machining challenges, applying a thin layer of long-chain organic media—like Sharpie, Dykem fluid, or stearic acid (the primary active ingredient in epilame)—it introduces a tensile surface stress that improves cutting performance by forcing micro-fractures in the swarf.
Image credit Purdue Engineering