A coupling part structured to engage with a complementary coupling part for interchangeably fastening a cutting head to a carrier of a rotary cutting tool. The coupling part includes a pair of coupling pins arranged opposite each other with respect to a central longitudinal axis and spaced apart from each other so as to form a receiving space structured to receive a central pin of the complementary coupling part. Each coupling pin includes a stop surface for transmitting a torque, a radially external outer surface, and a radially internal inner surface. At least one of the outer surface or inner surface is a clamping surface oriented in an obliquely inclined manner with respect to the central longitudinal axis for centering and clamping the coupling part.