2022 Volume 27 Pages 28-
When machining deep holes with a high aspect ratio on high-hardness materials, small-hole electrical discharge machining (EDM) is often used. In small-hole EDM, it is empirically known that the machining speed decreases as the machining hole becomes deeper. Hence, it is assumed that the debris stagnates and machining becomes unstable. Therefore, we have found the effect of suppressing the decrease in machining speed by using the grooved electrode. However, at that time, there was a problem because it was a self-made groove machining. Because it was formed by draw-cutting, the groove depth was not uniform and burrs were formed groove edge. In this report, the effect of a custom-made cross-sectional shape electrode using mass production equipment was investigated. Furthermore, it was clarified that the machining fluid ejection pressure affects the machining characteristics even when a normal pipe electrode is used.