What Is EDM Machining?

EDM machining uses electricity to shape metals and other products.

Manufacturing refers to the use of machines and tools to produce goods for sale. EDM, or electric discharge machining, is a manufacturing process that uses electricity to produce desired goods.

Definition

EDM machining, also known as die sinking and spark erosion, is the production of goods whereby the desired shape of the finished product is obtained via the use of electric discharges, or sparks. EDM machining is often used to modify hard metals difficult to machine by other methods.

Electrodes

The EDM machining process removes material from a workpiece, or piece of material being worked on, via electric discharges between two electrodes, or conductors used to make contact with part of a circuit. The electrodes are separated by a dielectric liquid -- a liquid that acts as an insulator. One electrode is the tool electrode, and the other electrode is the workpiece electrode. When the distance between these two electrodes decreases, the dielectric liquid breaks down, allowing current to flow between the electrodes. This vaporizes material from the electrodes in a controlled fashion, enabling the production of a desired workpiece shape.

Flushing

Once current flow in the EDM machining process stops, new dielectric liquid is added between the electrodes. This process, known as flushing, clears away debris from the workpiece.

References

• Tooling U: High Speed Machining
• "The EDM Handbook"; E. Bud Guitrau; 1997

Resources

• "Electrical Discharge Machining"; Elman C. Jameson; 2001