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 (B) 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 (B) 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 (B) 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), and wherein the torque transferring connection includes a telescopic coupling tube mechanism having a plurality of tube elements, the telescopic coupling tube mechanism being arranged coaxially with respect to the spindle axis, wherein a plurality of through holes are formed in a tube wall of an outer tube element having the largest diameter among the tube elements of the telescopic coupling tube mechanism , characterised in that the through holes are configured to enable an outflow of cooling and/or lubricating liquid from the inside of the telescopic coupling tube mechanism to its outside. - a spindle assembly including a workpiece spindle being configured to receive an elongated workpiece (B) 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 (B) 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 (B) 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), and wherein the torque transferring connection includes a telescopic coupling tube mechanism having a plurality of tube elements, the telescopic coupling tube mechanism being arranged coaxially with respect to the spindle axis, wherein a plurality of through holes are formed in a tube wall of an outer tube element having the largest diameter among the tube elements of the telescopic coupling tube mechanism , characterised in that the through holes are configured to enable an outflow of cooling and/or lubricating liquid from the inside of the telescopic coupling tube mechanism to its outside. <EOS>