Abstract: A rotary centering device for the transfer of a bar from the guiding channel of a feeder to a lathe, comprising a supporting element and provided with at least one circular seat in which a grip element for a bar is supported, the grip element being constituted by a bush which has a tubular portion and a plurality of sectors connected to the tubular portion, elastic elements being provided which act on the bush and are designed to control its axial movement between a first stop position, in which the sectors define a circular opening whose diameter is the same as that of the bar, and a second position, in which the sectors are moved until they form an opening to allow the passage of the bar pusher.