A disc for a fan rotor (with a pilot to connect to a rotating shaft, a hub and a plurality of blades) includes a flat circular portion connecting to the pilot at an inner edge and to the hub at an outer edge; a plurality of first circular cooling holes of a first diameter located around the inner edge of the disc; and a plurality of second circular cooling holes of a second diameter located around the outer edge of the disc, wherein the second diameter is larger than the first diameter.