A rotor for a threshing system of an agricultural combine and method for making the same, including a body of simplified, three part press fit construction including an inlet segment, a main body segment having threshing elements therearound, and a bulkhead to be connected to a drive mechanism. The inlet segment, main body segment and bulkhead are configured so as to facilitate press fit assembly thereof concentric about a rotational axis about which the rotor will be rotated during operation, while also minimizing eccentricities of those components. As a result, the manufacture of the rotor is simplified by the elimination of the need for an internal skeleton structure and associated welds and/or fasteners.