What are the three primary types of EDM processes, and how do their applications differ?

Electrical Discharge Machining encompasses three primary processes: Wire EDM WEDM, Ram EDM (also known as sinker, plunge, or conventional EDM), and Small Hole EDM Drilling (hole popper).

Wire EDM uses a continuous traveling spool of thin brass or coated wire in deionized water to slice through-profiles like a super-precision band saw, making it the standard choice for burr-free stamping dies, precision gears, and delicate thin-walled parts.

Ram EDM uses a shaped graphite or metallic electrode submerged in hydrocarbon dielectric oil to burn blind cavities, 3D injection molds, blind keyways, and internal threads into hardened steel or carbide.

Small Hole EDM drilling utilizes a rapidly rotating, hollow tubular electrode with high-pressure flushing to drill deep, straight starting holes and cooling passages into hardened alloys up to several hundred times the electrode diameter without drill wander or tool deflection.