In principle, EDM vertical erosion could also be carried out in a deionised water bath.
However, due to the achievable surface values, removal rates and wear values, a dielectric medium based on synthetic oil products is generally used in this case.
In principle, any electrically conductive material could be used as the electrode material in vertical erosion. Due to the material or process characteristics, only a few have prevailed in erosion. Nowadays, high-quality eroding graphite and electrolytic copper are mainly used in standard cases.
Tungsten copper is used in special cases, e.g. when carbide is to be eroded. Another exception is tungsten wire. This is specifically used to erode the smallest of holes.