Wire EDM

A wire EDM cuts with electrical sparks between a thin, continuously fed wire and the workpiece, in deionised water. Nothing touches the part, so there is no cutting force, and hardness does not matter as long as the material conducts electricity. The wire passes right through the part and follows a programmed path, leaving sharp internal corners and narrow slots that no end mill can produce.

Typical work is punches and dies, extrusion dies, mould inserts, and medical and aerospace parts in hardened steel, carbide or titanium. The upper wire guide moves independently in U and V, which tilts the wire for tapered cuts. Because the wire needs a start hole and cuts through, it cannot make a blind cavity. That is the job of a sinker EDM, which burns the shape of an electrode into the part.

Compare the X, Y and Z travels with the largest workpiece the tank accepts and its weight. Z height sets the thickest part. The taper angle at a given height, the range of wire diameters and automatic wire threading matter for unattended running. Check whether the machine cuts submerged, which helps on tall and interrupted sections.