What role do electrodes play in FastEDR?
FastEDR’s hand tool contains an electrode, and while you can’t see it while the process is running, it plays a crucial role.
The electrode is the active component that removes fasteners without ever physically touching them. It’s the reason the process involves zero mechanical force, which makes it safe for the operator to use, while virtually eliminating the risk of damage to high-value components.
Thanks to the electrode, FastEDR removes seized fasteners in a way that’s precise and traceable - something that conventional electrical discharge machining equipment was never designed to do.
The process
When FastEDR is in action, the electrode sits a fraction of a millimetre from the seized screw, and deionised water fills the gap between them. Voltage builds across the gap until the deionised water breaks down at its weakest point. A tiny, bright plasma channel, like a miniature lightning bolt, bridges the gap for microseconds.
That plasma channel is intensely localised and creates tiny holes in the screw’s surface (smaller than a grain of sand). The flowing deionised water sweeps away the dislodged metallic debris immediately, creating no FOD or swarf. This happens over and over again until the fastener has been eroded, which usually takes around 70 seconds. It can then be removed by hand because everything remains cool to the touch.
This is the part that often surprises people - the electrode wears down too, just much more slowly than the workpiece. Every spark erodes a tiny bit of both surfaces, but EDM electrodes are chosen from materials that resist erosion well (high melting point, good conductivity), so the ratio is heavily in favour of eroding the fastener rather than the electrode.
In slow motion, the process looks less like machining and more like a rapid electrical storm raining on the screw’s surface, with each tiny flash leaving a microscopic scar.
FastEDR knows when to stop removing material because its software holds preset parameters for specific fastener types, including the required removal depth. The system tracks progress using the electrode drive mechanism and encoder, stopping automatically when the target depth is reached. The operator does not need to make that judgement manually.
What the electrode looks like
FastEDR electrodes are made from either brass or copper, generally measuring about 5cm long. Custom electrode diameters can be produced quickly in-house, meaning FastEDR can be configured for unusual or non-standard fasteners without long lead times.
Electrodes are cylindrical, with one or more channels running through the middle for water flow.
The shape and geometry of the electrode are important because a smaller cross-sectional area means less material to machine away each time, which speeds up the process. It means more water can flow through the electrode, so debris is flushed away faster, which also improves speed.
Multi-channel electrode designs give greater flexibility in how material is removed, and allow the system to avoid leaving a central pip of uneroded material. This is beneficial in blind hole applications and in cases where the goal is not full removal but machining a new drive feature, such as a square recess, into a fastener where the original head has been destroyed.
Each electrode lasts for approximately ten fastener removals before it needs replacing, and replacements are straightforward, with the machine guiding the operator through the process.
Cost of electrodes
We understand that ongoing costs are an important factor in buying decisions. Electrodes are supplied in packs of five and cost around £25 each, so for every fastener removed, the cost is roughly £2.50, which is often cheaper than using a drill.