Working Principles Of Electrical Discharge Machining
                     
Description
Electrical Discharge Machining is a non-traditional manufacturing process that uses 
electrical energy instead of mechanical force to remove material from a workpiece. When 
machining operations such as CNC milling and turning fail to create the desired cut such as 
sharp interior corners or a very deep hollow, engineers frequently turn to Electrical 
Discharge Machining. The EDM method includes removing extra material from an object with 
electrical energy, resulting in the needed shape for any task.
Electrical Discharge Machining is similar to laser cutting and other similar technologies. The 
extra material is removed without the application of mechanical effort. This is why it is seen 
as a non-traditional manufacturing technique by many people. This procedure is helpful for 
molding and tooling in a variety of industries. This article will look at the working of electric 
discharge machining and the different types of Electrical Discharge Machining.
What is EDM Sparking?
EDM Sparking Processes is also known as the spark machining, eroding, die sinking or 
burning or wire erosion process. It is basically a process of metal fabrication that is achieved 
via electrical discharges (sparks). Edm Spark Machine removes unnecessary metal shaped 
by a series of rapidly current discharges between two electrodes.
Electrical discharge Machining Working Principle
The electrical discharge machining working process is based on the generation of sparks 
and metal removal through spark erosion. EDM spark erosion is the same as when an 
electric spark strikes a piece of metal and burns a small hole into it. This process generates 
heat which causes metal to be removed through erosion and evaporation. During this 
machining procedure, the workpiece and the tool must be made of conductive materials.

Different types of EDM
EDM is divided into three categories. This ensures that you have other options if one solution 
does not meet your needs. The different types of electrical discharge machining are:
Die sinking EDM
Die-sinking EDM or Ram EDM is an appropriate option when complex cavities need to be 
machined. A graphite electrode is first created in the reverse shape of the required hollow to 
create the die while submerged in a dielectric fluid by inducing a voltage between the die 
and the electrically conductive workpiece.
The die is gradually lowered towards the workpiece until it reaches ‘electric breakdown,’ at 
which point a spark passes the ‘spark gap.’ The material vaporizes/melts as a result, and the 
expelled particles are carried away by the dielectric fluid. A sequence of high-frequency 
sparks repeatedly removes material from the workpiece, accurately cutting the desired 
shape.
Advantages of Die Sinking EDM
Die Sinking EDM Processes has come far and done wonders for the production and 
manufacturing industry providing durable results with quality finishes.
● No polishing required after the process is complete.
● Achieves complex shapes that would otherwise be difficult to produce with conventional 
cutting tools.
Types of Die Sinking EDM Machines (ZNC and CNC)
ZNC EDM Machine
ZNC stands for :- Z axis Numerical Control. ZNC EDM Machines cut metals on a lateral plane. 
Here better surface finish can be achieved in bottom surface of job . Normally the process 
will be done while job is submerged in tank of edm oil.
CNC EDM Machine
CNC EDM Machines have superior cutting speed and have better surface finish in all 3 axis 
and are known for their high accuracy. Incorporated with Computer Numerical Controls, this 
will erode material and achieve better accuracy on all surfaces. This process will done with 
job submerged in a tank of EDM oil.
Wire Cut EDM
Wire erosion, also known as wire-EDM, is the process of cutting objects with thin wires. The 
wire is employed as an electrode in this type and the wire is fed constantly from the 
automatic feed with the spool during the procedure. If you need to cut the thing in the 
middle, drill a small hole in the object with the EDM drill, then slide the wire through the 
hole. Further electric discharge machining allows the wire to be secured using a diamond 
guide. The liquid is ionized water and the wires are made of brass (Brass is a mixture of 
copper and zinc , which have better tensile strength compare to copper)
There are many advantages of Wire Cut EDM such as:
1.Precise for 2-axis cutoff of small parts with better cost effectiveness than that of laser 
based cutting.
2. High Ppk/Cpk values.
3. Very versatile in cutting of hard and conductive metals.
Accutex a Taiwanese based leader in the machine tools industry, provides arrays of CNC 
general wire cutting EDM for our valued customers. Check out our Accutex Wire EDM 
Products.
Small Hole EDM
Small Hole EDM, as the name suggests, aids in quick hole drilling.It is also called Small Hole 
Drilling. The electrodes used in hole EDM are tubular, allowing the dielectric fluid to flow 
freely through them.
Unlike standard drilling technologies, Hole EDM can create extremely small and deep holes. 
Furthermore, there is no need to deburr these holes. This approach allows for effective 
drilling of precision holes faster than other methods, regardless of metal hardness or type.
Conclusion
For high-demand machining applications, electrical discharge machining remains the best 
option. It enables engineers to rearrange materials in difficult or impossible-to-reshape 
situations. This one-of-a-kind procedure aids in the production of high-quality components. 
However, even though it isn’t the most widely used CNC machining method, engineers rely 
heavily on it to create parts that are impossible to machine.
Also Read: What materials can wire EDM cut?
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