Abstract: A tool holder for an electric discharge machine has a top base, a securing collar, a positioning sleeve. an adjusting base and a rotating base. The top base has a central hole and an elongated opening communicating with the central hole. The securing collar is screwed into the central hole in the top base and has a central hole with a conical inner surface. The securing collar has multiple holes corresponding to the elongated opening in the top base. A positioning sleeve has a conical outer surface fitting with the conical inner surface in the securing collar. The adjusting base has a main shaft penetrating through the central hole in the positioning sleeve. Consequently, the locked condition of the main shaft is released by rotating the securing collar, such that the adjustment of the tool holder is convenient.

Abstract: A tool holder for an electric discharge machine has a top base, a securing collar, a positioning sleeve, an adjusting base and a rotating base. The top base has a central hole and an elongated opening communicating with the central hole. The securing collar is screwed into the central hole in the top base and has a central hole with a conical inner surface. The securing collar has multiple holes corresponding to the elongated opening in the top base. A positioning sleeve has a conical outer surface fitting with the conical inner surface in the securing collar. The adjusting base has a main shaft penetrating through the central hole in the positioning sleeve. Consequently, the locked condition of the main shaft is released by means of the rotating the securing collar, such that the adjustment of the tool holder is convenient.