Many manufacturing plants rely on machining of various methods as a way to produce their product. Nowadays and good machine shop will have started to use the technique of Electrical Discharge Machining, or EDM. EDM is also sometimes called spark eroding, die sinking, burning, spark machining or wire erosion, but whatever name is used the technique is the same. The term EDM is more widely recognized than these other terms and is therefore preferred.
EDM uses two electrodes with a dielectric liquid in between them. One of the electodes is the tool and the other electrode is the work piece, basically the piece of metal from which material is to be removed. Current is discharged between these two electrodes and material is removed from both the tool and the work piece.
When the tool is brought close to the work piece, the electric field between the two becomes more and more intense until current is discharged between the two. When material is removed from the two electrodes it needs to be removed. This is done by flowing more dielectric liquid over the work piece. The old dielectric fluid carries away the materiel. This is called flushing. Flushing is also necessary because with the large current discharge the dielectric fluid will lose its insulating property and is no longer useful. Replacing the fluid replenishes the insulating property.
EDM is often used to create prototypes for the aerospace industry. It is also used for creating dies for badges and jewelry. EDM can be very useful for small hole drilling, often used in electronics. An interesting application is for removing tools such as drill bits which have broken off inside a work piece.
EDM has some advantages and disadvantages. On the advantage side, EDM can make complex shapes that normal tools can’t create. It can also work very hard material and can create close tolerances. The tool does not contact the work piece directly so even delicate materials can be machined using EDM.
On the disadvantage side, EDM can be slow. Although complex shapes can be created, it is hard to get sharp corners. And because EDM is performed using electricity it uses a very high amount of power.
In conclusion, EDM is a very useful machining technique that is in wide use. It has some distinct advantages and disadvantages, so your machine shop will need to assess the need and determine whether EDM is right for their particular shop.

One of the most useful technologies in manufacturing is machining, as many parts needs to be created out of larger pieces and it is almost always better to create a part from one piece of material than needing to bond several pieces together. There are various types of machining that involve cutting or drilling, but an interesting form of machining is called Electrical Discharge Machining, or EDM for short. EDM is sometimes called die sinking, wire erosion, burning, spark machining or spark eroding, but because Electrical Discharge Machining is more commonly used it is the preferred term.
EDM involves using two electrodes with a dielectric fluid in between them. As these two electrodes are brought together the electrical field between them becomes more and more intense until there is a currency discharge between them. At this point material is removed from both of the electrodes. In the case of machining, one electrode is the work piece from which material is to be removed and the other electrode is the tool. Once the current has discharged the dielectric fluid must be flushed to remove material and remove the old dielectric fluid.
One specific type of EDM is called Wire EDM. In wire EDM the tool takes the form of a wire. This is useful because with every discharge part of the tool will be eroded away, and the wire can be kept on a spool and continually fed into the tool. With wire EDM the guides can move in several axes which allows very intricate shapes to be created. Wire EDM is often used to create dies and punches and other tools from metals that are too hard to machine with other methods. One very useful feature of wire EDM is the ability to make a tapered shape or a shape that transitions from one shape at one end to a different shape at the other end. The dielectric fluid which is used with wire EDM is water, which has the advantage of being both plentiful and cheap.
If the material you are cutting can’t be stressed wire EDM is very useful because it doesn’t require large forces to be exerted on the material to be machined. However there is a large cycling of heat to the piece which could be a disadvantage.
In conclusion, wire EDM is a valuable tool that many machine shops may want to consider using for making intricate shapes.

My brilliant nephew has graduated from college with his degree in electrical engineering. He interned with a company specializing in EDM – electronic discharge machining. Understanding just what it is that he produces has been a challenge for the whole family, but we think we have absorbed the very basics.
Electronic discharge machining is a manufacturing technique that has been in existence in one form or another since the 1700s. It is designed to craft complex and intricate shapes for machinery using electrical sparks (aka discharges). The process is used on electrically conductive materials and hard metals like steel and titanium, for which more traditional crafting techniques like metal milling and grinding are not as useful at obtaining the precise shape desired. The EDM process is able to create detailed designs in steel that is already hard, avoiding the need to soften the metal and then harden it again. This sort of alternate style of manufacturing is frequently categorized with services like water jet and laser cutting. At its most basic level, the process is akin to sculpting; whereby the electrical discharges are used to remove tiny bits of the metal so that the necessary design is achieved.
EDM applications have traditionally been used in the tool and die-making industry, but have gained widespread application in the aerospace and electronics industries as well. My nephew’s internship offered him opportunities to explore the different aspects of the technologies associated with electronic discharge machining, including ram, wire cutting, small hole drilling, and cavity EDM. He is now considered a skilled engineering-artisan who found himself in high demand when he graduated. Currently, his specialty is in creating prototype parts for an aerospace company. He really enjoys the challenge and creativity of applying EDM practices to develop innovative pieces that allow new products to come alive and enter the marketplace.
As you might imagine, our entire family is very proud of my nephew and his many accomplishments. His boss has suggested that he participate in the authorship of a research paper on techniques his company has originated. His success in this vocation has inspired the career ambitions of other youngsters in the family. In an age where good jobs have become increasingly hard to find, there is actually a dearth of students in the math and engineering programs in our colleges and universities. An ambitious student contemplating various career paths would do well to give engineering a second look. Opportunities in evolving processes like electronic discharge machining may offer the opportunity to apply talent and creativity to solve problems across the manufacturing sectors.