Abstract: The invention relates to toolholders and mechanisms for securing the toolholder to a lathe turret or tool indexer. One embodiment of the invention comprises a base adapted to be secured to a rotary lathe table via a mechanism receivable in slots or grooves which can be wedged and compressively secured about selected positions about an engagement surface. A second embodiment comprises a bore securable to a lathe table via both fastening and positioning mechanisms where the bore defines a dovetail groove receivable to a complementary tongue where the toolholder is securable to the bore in a cam locking mechanism.