Abstract: A face driver for centering and driving a workpiece to be chucked in a lathe comprises a support provided with a dead center member and several driving pins around the dead center member so as to be movable and pressable against the workpiece by a compression member acting against a pressure plate, the pressure plate is retained so as to be floating in the axial directions of the support, and it has parts or arms associated with the driving pins which are elastically deformable. This causes squareness errors of the workpiece to be chucked to be compensated for automatically at low structural cost.

Abstract: A tool fastening device comprises a drawbar (21, 22; 47, 48) for clamping a tool holder (10; 40) to a spindle (11; 41) of a machine tool by frictional engagement with a conical bore therein. The drawbar is connected to the tool holder by radially expansible locking means (23; 50) on the drawbar. The locking means is actuated by means of an expansion rod (28; 52). For purposes of facilitating the operation of the expansion rod there is provided forcing means (30; 57) which continuously forces the expansion rod toward the tool holder.