AbstractTen materials with a wide range of microstructures and properties have been electrodischarge machined using copper and graphite electrodes with three pulse energies, and their machining rates, roughness, microstructure, micro hardness, cracking behaviour, and - for the white cast iron - dry sliding wear behaviour deternlined. Materials that are difficult to machine by conventional means (e.g. metal matrix composites, white cast iron, and high silicon cast iron) could be readily processed. Machining rates were approximately a linear function of the square root of pulse energy. A similar topography, which was difficult to quantify, was observed on all the materials. Surface roughness of the tool steel was a function of cube root of pulse energy. Hard surface layers occurred on the ferrous materials, but in some non-ferrous materials softening occurred. Extensive cracking occurred only in steels and cast irons containing a high concentration of chrOlnium. Electrodischarge machining increased the wear resistance of white cast iron fivefold.