EDM Services

During the electrical discharge machining process, a workpiece is submerged in a dielectric fluid. An electrode is then used to produce an electric spark between itself and the workpiece, melting localised areas of the workpiece through thermal energy. This process happens hundreds of thousands of times per second, breaking down the workpiece to produce a desired shape.

Electrical discharge machining occurs through methods such as wire EDM, die sinking EDM, and hole drilling EDM.

EDM is a non-traditional machining method, used to shape a workpiece through thermal energy, as opposed to more traditional tooling such as a milling machine.

The two main types of EDM machines include die sinking EDM and wire EDM.

Die sinking EDM uses specially formed electrodes which are lowered into the workpiece, creating a negative version of the electrodes shape; die sinking can be used to shape the centre of a workpiece, and for producing complex shapes.

Wire EDM uses a thin consumable wire to cut the outside of a workpiece in order to shape it. A new supply of wire must constantly be fed in order to continue the process since the heat produced consumes the wire.

EDM hole drilling uses a spinning pipe-shaped electrode to melt holes into a workpiece, similar to the process of how a manual drill produces holes.

Dielectric fluid in EDM is a non-conductive fluid, typically oil based, which helps cool the electrical discharge machining process, as well as wash away excess material produced during the process. After a workpiece has been machined, dielectric fluid is used for flushing – a final wash of the workpiece to remove excess material.

Electrical discharge machining can produce a mirror-like surface finish compared to traditional machining methods, which can cause a directional lay due to the movement of the cutting tool. Because an electrode does not come into contact with a workpiece during the EDM process, there is no lay.

Better quality finishes can be achieved with a slower EDM process.

ECM stands for electrochemical machining, which uses electrolysis to dissolve a workpiece. Whilst EDM and ECM are both non-contact machining methods, electrically powered, which work on conductive materials, there are some differences between the two.

EDM uses a dielectric fluid as opposed to the electrolyte solution in ECM, which is used to conduct the electric current. The tooling used for EDM and ECM are moreover different; EDM produces heat, so can consume or alter the electrode tooling, whereas ECM does not.

The advantages of EDM include: EDM works on hardened materials; tooling does not come into contact with the workpiece, meaning no mechanical stresses, distortion, or burring will occur. Complex shapes can be machined; and tight tolerances can be achieved.

The disadvantages of EDM include: electrical discharge machining only works on electrically conductive materials; the heat produced can cause tool wear; it requires power to work, often leading to high power consumption; material removal rate may be slower than alternative methods.