Electrical Discharge Machining | MoldMaking Technology

EDM stands for Electrical Discharge Machining. A good way to describe the material erosion process of an electrical discharge machine is to think of the EDM spark as a shovel. Whether you are digging a hole or electrically removing material to form a cavity with an EDM, you remove material one shovel, or one spark, at a time. To dig a hole/cavity faster, you can use a bigger shovel (more power) or shovel faster (shorter pauses between sparks) or use a different-shaped shovel (electrical waveform).

When you consider that the speed of the EDM process may vary from 1,000 to 150,000 sparks per second, a machine that helps you choose the correct waveform, select the maximum power allowable by geometry, and automatically adjust the flush and cooling time between sparks is a pretty difficult machine to beat.

The EDM process, much like other metal-removal processes, presents two main difficulties that must be overcome: heat and contamination. Each tiny spark creates heat, and the more power and the higher the frequency of the spark, the more heat is created. A good spark should take a large shovel out of the workpiece and a very small piece of the electrode.

Source: Machining 101: What is Electrical Discharge Machining?