Acutech logo

What is the spark erosion process and what is it used for?

The Spark Erosion Process

Spark erosion (also called electrical discharge or electro-discharge machining) is a subtractive machining method. It’s used to fashion a particular shape (including a difficult one if required) with the use of sparks or electrical discharges. It can help you create the piece you’re looking for, especially if what you are after is quite complex. For decades, it’s been used as a popular way of manufacturing complex, intricate forms.

This procedure can take away material from an item via current discharges between a couple of electrodes which are separated by a dielectric liquid subject to voltage. Throughout, this liquid acts as both conductor and cooling agent.

Material is removed by converting electrical energy into heat, kicking off a melting process inside the electrodes but without any mechanical abrasion.

What are the benefits of spark erosion?

  • You can create intricate detailing that would otherwise be difficult or impossible to achieve using alternative, standard cutting procedures
  • It’s a particularly handy process when changing very hard materials including press tools; there’s no limit to how hard the material you work with can be
  • Spark erosion also means you can achieve a good surface finish and drill really fine, small holes
  • Getting the end result you want is fairly easy with this method, the electrode does wear with the discharge but where tight tolerances are required a finishing electrode is used.
  • You can work on weak materials or intricate pieces with no distortion
  • Equally, it’s possible to work to really tight tolerances of up to 0.1 microns; this gives you a feel for the potential level of detail that’s achievable
  • Multi-feature sparking can be used across a single operation, incorporating multi-axis erosion
  • Its flexibility means jobs can carry on during ‘lights out’ periods such as weekends, evening and public holidays

What is spark erosion used for?

If a material has an electrical conductivity of at least 0.01 S/cm, the chances are you can work it using spark erosion. That includes the majority of alloys and metals, including:

  • Copper and associated alloys
  • Tungsten
  • Numerous stainless steels
  • Carbide
  • Aluminium
  • Magnesium alloys
  • Graphite
  • titanium


What’s more, the versatility of spark erosion means that you can use the process on a huge range of jobs, from small jewellery to aircraft landing kit or to cut a submarine hatch’s keyway hinge.

Use us for spark erosion cutting

At Acutech Precision Engineering, we believe spark erosion is a huge asset for any organisation looking to machine products in a way that would otherwise be all but impossible.

Talk to us about what you need. We’ve provided spark erosion in Norfolk for two decades and do so to an extremely high standard, either from your own vision or from drawings we’ve created for you. Get in touch today.