Abstract: A coupling for use in a rotary ball valve having a spherical ball with a passageway therethrough for controlling the flow of fluid through the valve. The coupling is particularly suited for use with non-metallic, for example, ceramic, spherical balls which are rotated by torque applied to a metallic actuator shaft. The coupling includes a plurality of depressions and protrusions formed at the interface of the non-metallic and metallic components. The depressions and protrusions are positioned away from the central axis of the spherical ball. A cushion can be interposed between the metallic and non-metallic components to further disperse the force applied to the non-metallic component. The depression and protrusions can be tapered and oriented at an angle with respect to the central axis so that as torque is applied to the shaft the non-metallic component is rotated without breakage thereof.