Die holders are used on production machines like single-spindle lathes, multi-spindle and cnc lathes, machining centres, drills and transfers. They are used for all threading operations and greatly improve tool life by preventing frequent breakages. The part of the tool on which the die is mounted can slide axially thanks to internal springs and also has a slight radial play compared to the part that is mounted on the machine. The play of the internal springs is crucial during the machining phase when the direction of rotation of the die is reversed. In addition, the axial and radial play compensates for alignment errors between the machine spindle and the workpiece to achieve high quality machining. The die holder spindles are produced with certified top quality steel, they are hardened and completely grinded.