A rotor core (100, 110) for an electrical motor with a rotational axis (6) and a central opening (200) to take up a shaft (4) of the electrical motor turning around the rotational axis (6), with the central opening (200) having a peripheral edge (201) with at least one attachment section (242), designed for attachment of the rotor core to the shaft by press fit, and at least one centering section (244), wherein the at least one centering section (244) and the at least one attachment section (242) are placed in different sections of the peripheral edge (201) in the circumferential direction (tangentially).