Wire & Spark Erosion (EDM) Companies UK
Electrical discharge machining (EDM), also known as spark erosion, is a non-contact machining process that removes material using electrical discharges between an electrode and the workpiece. Because there is no mechanical cutting force, EDM can machine any electrically conductive material regardless of hardness — making it indispensable for hardened tool steels, carbide, and superalloys that are difficult or impossible to machine conventionally.
This category lists UK subcontract wire EDM and die-sink EDM companies serving the toolmaking, aerospace, medical, and precision engineering sectors.
Wire EDM
Wire EDM uses a continuously fed thin wire (typically 0.1mm to 0.3mm diameter brass or coated wire) as the electrode to cut through the workpiece like a bandsaw, but with a cut width (kerf) of only a fraction of a millimetre. This enables the production of intricate profiles, fine slots, and complex shapes in hardened materials to tolerances of plus or minus 0.005mm or better. Wire EDM is extensively used for press tool and die manufacture, extrusion dies, precision gauges, medical components, and prototype parts.
Modern wire EDM machines operate with multiple passes — a rough cut followed by one or more skim cuts — to achieve both tight dimensional accuracy and excellent surface finish. Submerged machining in deionised water provides stable cutting conditions and good flushing of the spark gap. Workpiece heights of 400mm or more can be accommodated on larger machines.
Die-Sink EDM
Die-sink EDM (also called sinker EDM or conventional EDM) uses a shaped electrode — typically machined from graphite or copper — to erode a mirror image of the electrode shape into the workpiece. This process excels at producing complex three-dimensional cavities, ribs, and surface textures that would be difficult to achieve by milling, particularly in hardened tool steels. Applications include injection mould cavities, die casting dies, forging dies, and specialist tooling.
Micro-EDM and Small Hole Drilling
Micro-EDM extends conventional EDM into the realm of miniature and micro-scale features, producing holes, slots, and profiles with dimensions below 0.1mm. EDM small hole drilling (also called fast hole drilling) produces small-diameter through-holes in hardened materials and is widely used for turbine blade cooling holes in aerospace applications and starting holes for wire EDM operations.
Search this directory for UK EDM specialists by machine type, workpiece capacity, material capability, and industry accreditation.