Die sinking EDM, wire EDM, and hole drilling EDM are 3 common types of electrical discharge machine.
The distance between two places can be determined with electronic distance measurement (EDM) by observing the phase shifts of electromagnetic waves as they propagate along a straight line.
Therm energy is used instead of mechanical force when the material is extracted from a workpiece by electrical discharge machining (EDM). Electrical sparks are used in the range of around 8000o C to 12000o C. 
The process is also referred to as spark machining. When conventional machining methods, such as milling and turning, fail to yield the desired result when cutting a particularly sharp interior corner or a deep cavity, engineers frequently resort to EDM.

Explore EDM's various electrical discharge machining types and benefits by exploring electrical discharge machining.

1.    Die Sinking EDM

Electro-discharge machining is the method of choice for making intricate cavities in parts. The most successful method is die-sinking EDM, also known as sinker, conventional, volume, or hole EDM. It's also how CNC machines deal with the problem of sharp interior corners. An electric spark is created between a graphite or copper electrode and the workpiece using a dielectric fluid.
Initially, a reverse-shaped electrode corresponding to the desired cavity is manufactured. The die is made from this. Dielectric fluids, such as oil, are used to produce a voltage between the die and the electrical conductor object.
The spark jumps the spark gap as the die is gradually brought closer to the workpiece, causing the electric breakdown. This causes the material on the workpiece to vaporize and melt, and the expelled particles are then swept away by the dielectric fluid. In many cases, a tiny bit of the electrode gets eroded.
The desired shape is created and accurately cut out of the workpiece as a sequence of high-frequency sparks removes tiny amounts of material at a time. 
Below is an illustration of the electrical discharge machining (EDM) method of die sinking:
Everything is under strict control thanks to precision machining when it comes to the servers, the power supply, and the placement of the electrodes.

2.    Wire EDM.

The wire electrical discharge machine, also known as wire erosion, is commonly used to create extrusion dies. Put differently, and it cuts the same way as die-sinking does. In this case, however, the die has been replaced by a thin electric charge wire acting as the electrode.
 Machines generate a flat surface on an otherwise three-dimensional object, much like a cheese cutter would be used to create a flat surface on cheese.
The distance of the wire is usually between 0.05mm to 0.35mm. In order to prevent burnt wire and ensure accurate cutting, a new spool of wire is automatically fed into the machine at regular intervals during the machining operation. 
By using this method, you may make highly exact incisions. Keep in mind that wire EDM alone won't be able to provide you with real square corners if you want to cut sharp inside corners. Depending on the diameter of the wire, the radius produced by the wire and spark gap will be anywhere from 0.13mm to 0.15mm.
Small dogbone corners can be used to make square interior corners if that isn't enough for your project. 
Find out more about the best practices for machining crisp internal corners by reading our guide on square-corner machining.
The middle of a workpiece may be a better place to begin a cut than the edge in some cases. For instance, an extrusion die's center must be machined to accommodate a complicated shape. In that situation, wire EDM machining requires a small hole, which can be drilled with hole-drilling EDM.

3.    Drilling holes electrical discharge machining

To create holes, hole drilling electrical discharge machining (EDM) is used. In opposition to more conventional ways of hole drilling, this approach may manufacture tiny and deep holes with pinpoint precision and without needing further deburring.
This technique relies on the same core concepts of die-sinking electrical discharge machining (EDM). As a pulsing cylindrical electrode deep cuts into the material, dielectric fluid is fed into the cutting area.
This method allows for designing highly complex cooling channels within the blades, making it essential for advancing high-temperature turbines.

Benefits of EDM

1.    Design flexibility
Cutting to forms and depths that would be unachievable with conventional machining technologies is one of the key benefits of electrical discharge machining. This category contains undercuts and internal corners cut to a perfect 90 degrees. An additional perk of the machining process is that it does not produce a burr.
To learn more about what may be achieved with CNC and EDM, check out our design standards for machining.
2.    The machining process had no distortion.
Unlike in conventional machining, the tool is always maintained at a safe distance from the workpiece. 
There is no deformation since no forces are operating on the component. This makes it possible to machine excellent details without worrying about cracking. Also, because there is no distortion, tolerances as small as +/- 0.012mm are possible.
3.    Superb level of surface quality.
Outdated material extraction methods, like Milling machines, produce machining marks on the workpiece. Since there is no inherent direction to the surface finish in EDM. 
It is possible to achieve a mirror-like quality without further processing. However, some small bead blasted-like textures may remain after rapid EDM processing.
For a more in-depth analysis of surface roughness ideal for your CNC machining job, please refer to our guide on the subject.
4.    Accuracy.
EDM's great accuracy makes it ideal for creating prototypes and small parts. This method, for instance, sees widespread use in the automotive industry, where minute engine components must be manufactured with extreme precision.
5.    The hardness of the material does not have any effect.
EDM is distinguished because it can cut through any material, provided that the material involved is conductive. Because of this, abrasive materials like Inconel and tungsten carbide may be machined.