Abstract: A sucker rod assembly is disclosed for use in oil well pumping apparatus. The assembly is constructed of a rod and a steel rod-end fitting. A unitary threaded head at the end of the rod is screwed into a socket in the rod-end fitting. The threaded head is of enlarged diameter and a tapered shoulder is provided at the juncture of the rod in the head. The fitting has a cylindrical socket with a threaded portion at the bottom and an unthreaded flange adjacent the outer end. After the head is screwed into the socket the flange is extruded into surface engagement with the tapered shoulder to provide a mechanical interlock between the rod and the fitting.