Abstract: The six sides or angles surfaces of a part are automatically machined on a CNC or NC machining center by securing the part to a fixture plate which is mounted on a platen supported by a U-shaped frame for tilting movement between horizontal and vertical positions. The frame is secured to a pallet of the machining center, and the platen is tilted in response to rotation of twin ball screws driven by a wrench transferred to the spindle of the machining center by an automatic tool changer. In each position, the platen is precisely located and clamped to the frame by a plurality of units each including a shot pin which has a threaded end portion for engaging a corresponding nut within the platen in response to rotation by a dual-torque wrench also transferred to the spindle by the tool changer.