Abstract: A window crank assembly for casement windows comprising a metal window crank having wing type hand grasp members extending laterally in both opposite directions from a central hub and a plurality of insert members, which are preferably metal but may also be plastic, receivable in the cavity of the hub, each of the insert members having an insert cavity of a different cross-sectional dimension and internal configuration to match the different cross-sectional dimension and external configuration of the different crankshafts of casement window operators made by the various casement window manufacturers. A set screw extends through aligned apertures of both the window crank hub and one of the inserts when received therein to bear against a portion of the casement window crankshaft received in the insert cavity which is inwardly thereof from an enlarged outwardly projecting spline portion of the crankshaft.