Abstract: A motor spindle for causing rotation of tools on a machine tool has a spindle motor with a motor shaft and a spindle shaft driven by the motor shaft and having a tool clamping means. From the tool clamping means there extends through the spindle shaft and the motor shaft an axially sliding draw rod for clamping tools or tool receiving means. The motor shaft is supported in a rotatable fashion, independently of the spindle shaft in a motor housing and the spindle shaft is supported independently from the motor shaft in a spindle housing, which is attached to the motor housing in a detachable manner. The spindle shaft is coupled in an interlocking manner in the direction of rotation with the motor shaft but is able to freely slide in it.