Spindle apparatus for use at a machine tool, in particular a lathe, comprising: - a spindle assembly including a workpiece spindle being configured to receive an elongated workpiece and a spindle motor for driving a spindle rotation of the workpiece spindle about a spindle axis of the workpiece spindle; and - a rotary guide-bush assembly (200; 200A) being axially arranged with the workpiece spindle with respect to the spindle axis, the rotary guide-bush assembly including a rotary guide-bush configured to receive the elongated workpiece and being supported at the rotary guide-bush assembly to rotate with the elongated workpiece received in the workpiece spindle about the spindle axis while enabling a movement of the elongated workpiece in the direction of the spindle axis; wherein the spindle assembly and the rotary guide-bush assembly (200; 200A) are configured to connect to each other by a torque transferring connection (500; 500A, 500B; 500C; 500D; 500E; 500F) arranged between the spindle assembly and the rotary guide-bush assembly (200; 200A) along the spindle axis so as to transfer driving torque during acceleration or deceleration of the spindle rotation driven by the spindle motor to the rotary guide-bush of the rotary guide-bush assembly (200; 200A), characterized in that the rotary guide-bush assembly includes a clamping portion (210A; 270A; 270B) configured to clamp the elongated workpiece, which is received in the rotary guide-bush and in the workpiece spindle, so as to directly transfer the driving torque applied from the spindle motor during a driven acceleration or deceleration of the rotation of the workpiece spindle through the clamped elongated workpiece for driving a rotation of the rotary guide-bush synchronized with the driven acceleration or deceleration of the rotation of the workpiece spindle. - a spindle assembly including a workpiece spindle being configured to receive an elongated workpiece and a spindle motor for driving a spindle rotation of the workpiece spindle about a spindle axis of the workpiece spindle; and - a rotary guide-bush assembly (200; 200A) being axially arranged with the workpiece spindle with respect to the spindle axis, the rotary guide-bush assembly including a rotary guide-bush configured to receive the elongated workpiece and being supported at the rotary guide-bush assembly to rotate with the elongated workpiece received in the workpiece spindle about the spindle axis while enabling a movement of the elongated workpiece in the direction of the spindle axis; the spindle assembly and the rotary guide-bush assembly (200; 200A) are configured to connect to each other by a torque transferring connection (500; 500A, 500B; 500C; 500D; 500E; 500F) arranged between the spindle assembly and the rotary guide-bush assembly (200; 200A) along the spindle axis so as to transfer driving torque during acceleration or deceleration of the spindle rotation driven by the spindle motor to the rotary guide-bush of the rotary guide-bush assembly (200; 200A), characterized in that the rotary guide-bush assembly includes a clamping portion (210A; 270A; 270B) configured to clamp the elongated workpiece, which is received in the rotary guide-bush and in the workpiece spindle, so as to directly transfer the driving torque applied from the spindle motor during a driven acceleration or deceleration of the rotation of the workpiece spindle through the clamped elongated workpiece for driving a rotation of the rotary guide-bush synchronized with the driven acceleration or deceleration of the rotation of the workpiece spindle.