Abstract: A nut screwed around a rotating shaft with a view to securing a part to said shaft and to cooperate with a fixed sensor sensing a quantity of material in a pre-defined volume to measure the speed of rotation of the shaft, including a ring of teeth separated by slots. At least a portion of the teeth includes at least one recess maintaining the clamping function of the ring of teeth, the at least one recess forming, with notches separating the teeth, respective material deficit intervals detected by said sensor when passing through the detection volume during the rotation of the nut. A method of using the nut with a sensor in a rotational speed measuring device and the production of same.

Abstract: The invention concerns a nut (1) intended to be screwed around a rotating shaft (5) with a view to securing a part (2) to said shaft and to cooperate with a fixed sensor (12) sensing a quantity of material in a pre-defined volume in order to measure the speed of rotation of the shaft, comprising a ring of teeth (10) separated by slots (11), said nut being characterised in that at least a portion of the teeth (10) comprises at least one recess (14, 16) maintaining the clamping function of the ring of teeth, said recesses forming, with the notches separating the teeth, respective material deficit intervals intended to be detected by said sensor when passing through the detection volume of same during the rotation of the nut. It also concerns the use of this nut with a sensor in a rotational speed measuring device and the production of same.