Abstract
It has been known that when micro hole machining was carried out by EDM using a straight electrode, the hole diameters became different at the inlet and outlet of the machining. This shape irregulality is caused by wear of the electrode and eroded particles. In this paper, a new method is proposed for diminishing the diameter differences of the micro hole and forming the straight micro hole by EDM using a stepped electrode. Following experimental results were obtained.(1) The micro hole diameters'become different at the inlet and outlet of the machining by using a straight electrode.(2) The difference in the diameters of a micro hole is diminished and the straight micro hole of desired diameter can be machined by using a stepped electrode.
