EDM, what is it, and how does it work?

Electric Discharge Machining or EDM is a process that uses electrical sparks to erode metallic work-pieces. It is capable of some incredible things that cannot be done using any other machining process.

There are two main categories: wire EDM and sinker EDM; each has a different application.

Implant Mechanix Inc has both, and our wire EDM is one of only a few in North America with a fully interpolating rotary axis.

This rotary axis allows the machining of spiral and other complex shapes. It can also be used as a precision indexer.

Wire EDM is sometimes described as “the glorified electric bandsaw” and that is a good way to think of it, but our “bandsaw” can cut amazing shapes to very tight tolerances using a thin brass wire as the cutting electrode.

Sinker EDM can also produce very complex shapes in very hard materials with high precision, but it uses a shaped electrode to burn its way into a workpiece, and can make blind features like a square cornered pocket whereas wire EDM cannot.

Both processes produce a bur free cut and are capable of fine finishes.

EDM is a slow, expensive process. The rule of thumb is “if you can machine it by other means, do so!” EDM shines when you can’t do it by other means.