A steering shaft for a steering system of a motor vehicle, comprises an inner shaft mounted axially displaceably in a hollow shaft, wherein a rolling bearing having multiple metallic rolling elements, which are disposed axially in at least two rows, is disposed between the hollow shaft and the inner shaft. By means of this, the structural length of the hand tool is reduced, servicing is simplified and the production costs are lowered. For example, when the load to the module is not very high, the clock controller continuously lowers the frequency of a system clock signal to be supplied to the module and continuously lowers the power supply voltage to the module.