A spindle motor for use in hard disk drives having a base plate, a stationary shaft, a rotationally driven rotor, and a bearing system rotationally supporting the rotationally driven rotor. The shaft is fixedly mounted on the base plate. The base plate includes a drilled hole for insertion of a portion of the shaft such that this shaft's portion and the inner surface of the hole define a joint length l, when this portion is pressed into the drilled hole. The shaft has at least one notch located along the shaft's circumference and interrupting the joint length l.