What does dielectric fluid do in EDM, and how does it remove swarf?

Dielectric fluid, such as hydrocarbon oil or synthetic fluid, has three functions:

• Insulation: It insulates the gap until electrical breakdown occurs, allowing a controlled spark.
• Quenching: It cools the vaporized metal particles after each discharge.
• Flushing: Circulation carries solidified particles, or swarf, out of the gap and into the filtration system, helping prevent bridging and destructive DC arcing.