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The Fundamentals of Wire EDM

There are many different computer numerical controlled machining processes in manufacturing, but one process in particular has grown in popularity. With recent advancements in technology, Wire EDM machining has become increasingly widespread in manufacturing. Wire EDM parts are widely used in many different industries and these machines have a range of applications in manufacturing.

What is Wire EDM Machining?

Wire electrical discharge machining, or wire EDM is a computer-controlled machining process that, like many other traditional machining processes, removes material from a bar stock. However, unlike most traditional machining, wire EDM shapes the bar stock by means of spark erosion rather than having the tool come into direct contact with the material.

In Wire EDM, the metal part to be machined is submerged in a dielectric fluid with a wire. By using electric discharges between the wire and the part, material is removed from the part, creating complex, delicate shapes. As the wire gets closer to the metal part, the electric current can pass more easily between them, leading to the separation of material with each spark.

Wire EDM Machining has many advantages

Because of the way in which material is removed, there is far less stress on the bar stock. Wire EDM can machine even hard or fragile materials into tiny, delicate, or complex parts, so long as the stock material is conductive. And, these machines can do this without causing the usual stress that contact machining produces. As a result, Wire EDM parts are not bent or warped. 

Also, because these machines can produce pieces without the stress of contact between the stock and the tool, they make parts with smooth surfaces finishes that are free of burrs. The parts can be brought to incredibly close tolerances and are completed without a need for any secondary processes. This reduces time and labor costs, while increasing the production efficiency. 

Since Wire EDM requires an electrical field to work, these machines can only process conductive materials. They can be more expensive than more traditional CNC turning and milling processes, and require well-trained personnel to run. However, these machines can greatly reduce production costs, as they can produce metal parts efficiently and without the need for finishing processes. Also, because of the use of spark erosion, there is a reduction in material costs and wastes as well.

Some common applications of Wire EDM

Wire EDM is ideal for parts with complicated shapes or patterns, and especially very small parts. Because there is no mechanical force on the part being machined, wire EDM machines can create very delicate pieces, or work with delicate materials without distorting them. These versatile machines are more commonly used to manufacture highly-detailed parts for the medical, aerospace, electronics, and automotive industries, as well as create tools that complement other machining processes.

The versatility and cost-effectiveness of these types of machines is particularly useful for prototyping, and can be used for projects that are low or high volume. Most often, they are used to manufacture metal components and tools at lower volumes, or parts that require low levels of residual stress.

At Small Parts Machining, we mainly use Wire EDM to build screw machine tooling to be used in our other production machining. Our wire EDM machine cuts high speed steel and carbides, which we then use in our screw machining and tooling in order to make high production runs. While our primary focus is not in wire EDM, we use it to complement our other machining processes in order to produce the best products possible.