EDM Graphite Electrodes: Grade Selection, Machining & Performance Benchmarks

Why Graphite for EDM

Graphite electrodes now account for over 70% of EDM tooling globally, displacing copper for all but the finest surface-finish applications. Key advantages: 3–5× faster machining, lighter weight enabling larger electrodes, and superior performance in deep-cavity and rib applications.

Grade Selection by Application

Machining Guidelines

• Use carbide-tipped or PCD tooling — HSS wears too rapidly
• Dry machining preferred; if coolant used, avoid water-based for fine-grain grades
• Surface speed: 200–500 m/min for milling; 0.1–0.3 mm/rev feed
• Dust extraction essential — graphite dust is electrically conductive