What Is Wire EDM And How Does It Work?

Electrical discharge machining or EDM is a relatively new process that uses the power of an electro thermal spark to remove the surface material of a conductive workpiece. It has been available to use for the last half a century but has become increasingly more important in industries where precision surfaces and tight tolerances are a requirement.

The Basics of Wire EDM

This is a very specific process that is completed in a dielectric water bath. Both the single strand of wire from the tool as well as the metal workpiece are submerged in the de-ionized water. There is also a gap between the end of the wire and the surface of the conductive metal workpiece. The wire acts as an electrode, and the spark jumps across the gap, which is less than the thickness of human hair. In the process, the material is removed from both the wire and the surface of the metal.

This removal is extremely precise and can be highly effective even on very hard metals. This includes exotic metals that are difficult to machine with other methods. With other methods that use direct contact of the cutting tool with the metal’s surface, the heat produced from the friction can distort the surface, leading to problems with maintaining tight tolerances. The use of wire EDM, where the surfaces do not touch, is the ideal alternative.

Wire EDM is a precision process that is essential in creating many different types of highly complex parts. In addition, it is a process that does not require additional thermal treatment, making it cost-effective to create molds, dies, and tools.