There are two different types of EDM services we offer at Twin City EDM and Manufacturing. These are wire EDM, sometimes called wire-cut EDM, as well as sinker EDM.

Often our customers are not sure which process is the best for their manufacturing needs. To help provide some guidance, here is a general overview of the process of sinker EDM, which is the most traditional or conventional options.

Both types of EDM use the same basic technology of the use of electrical discharge to remove small chips of metal from the surface of the workpiece. The use of a dielectric field and dielectric fluid provides the environment to allow this action while the fluid washes away the tiny chips, keeping the workpiece free from debris that could impede the process.

Sinker EDM Process

The process of sinker EDM uses the charged electrode to actually burn into the surface of the workpiece to create a shape. The workpiece itself is immersed in oil, which keeps debris from accumulating on the surface.

The electrodes used in sinker EDM will be made out of different materials that will be better matched to different metals and alloys in the workpiece. They are most often made of copper tungsten, brass or, more commonly, from graphite.

Unlike wire EDM, sinker EDM does not cut all the way through the part. Rather, it is used to create shapes on the surface that can be set to any required depth.

The advantage of using this EDM method is that it can be completed on any material that is electrically conductive. It allows for very complex shapes to be formed, even in the hardest materials used in tool and die manufacturing.

The types of shapes and tolerances possible through this technology make this a very good choice for even the most precise manufacturing processes. It is ideal when there are corners that require a very tight radius.