Advantages and Disadvantages of EDM

Machining parts with the electrical discharge method is a manufacturing method that’s especially preferred in die-making. With this method, called EDM, we can cut and shape various workpieces. So what are the advantages of EDM? Why is it preferred? Let’s look at its weaknesses (disadvantages) compared to other manufacturing methods.

The Advantages of Material Removal by EDM

areas of use of the EDM method — The most important advantage of EDM is that it can machine regardless of the material’s hardness.

The ability to produce carved features and screw threads in hardened steels and hard metals with sinker EDM.
Being able to manufacture, to precise shape and dimensions, parts that need to fit together, like a cutting plate and its male punch in blanking dies, is one of the advantages of EDM machining.
Another advantage of EDM machining is achieving a surface quality that also provides good retention for lubricants.

Complex Geometry Advantage

EDM can machine internal geometries too complex to be produced with conventional cutting methods.

Slow Machining Speed

EDM generally has a slower machining speed compared to conventional machining.

High Energy Consumption

EDM machines can consume relatively high energy due to continuous spark generation.

The Disadvantages of EDM

The biggest disadvantage of an EDM machine is that it removes material much more slowly than other machines. Efforts have been made to offset this disadvantage by making the machine capable of automatic operation. Once the initial setup is done, the operator can work on other machines. When the job is finished or an abnormal condition occurs, the machine shuts itself off and alerts the operator.

advantages and disadvantages of edm machining — Machining with EDM often requires other machines to prepare the electrode

A second limitation of the machine is electrode (template) preparation and consumption. The machine depends on other machines to prepare its electrode. But with their help, it can easily do many things that they would find very difficult, or impossible, to do on their own. As an example, machining a rectangular pocket with sharp corners in a single piece isn’t possible with a milling cutter. But a male rectangular shape is easy.

disadvantages of edm machining electrode — An electrode prepared for a part to be shaped by sinker EDM

For example, machining the shape above into a female die is very difficult with other machining methods. This becomes possible with EDM. However, other machines are still needed to machine the electrode. Some other disadvantages of EDM machining:

Low erosion capacity during fine material removal.
Dimensional and shape deviations that can occur due to electrode wear.
High machine cost.
Structural changes in the thin surface layer, caused by the high heat released during the erosion process.

Related Questions

Instead of mechanical cutting, the material is melted and vaporized point by point with small sparks. This fine, incremental machining process naturally takes longer than a tool directly cutting the material.

Since no cutting force is needed, the electrode can reach narrow, complex cavities a conventional tool couldn’t enter, transferring its negative shape onto the workpiece. This makes it possible to produce details, like sharp internal corners, that are difficult to achieve with mechanical cutting.