Abstract
In EDM of deep hole, the machined hole generally becomes concave shape by the occurrence of secondary discharges in the side gap. By using flange type electrode, the occurrence of secondary discharge could be reduced. In this report, the effects of the shape of flange type electrode on the machined result were investigated. Experimental results clarified that a straight deep hole could be attained by using flange type electrode with sufficiently large step, and the diameter of machined hole decreased with an increase of the step difference. Also, EDM performance became better, even if a EDM machine with ball screw drive was used.
