Abstract: In the present invention a suitable end fitting is provided for fiberglass or plastic rods wherein the interior of the end fitting is defined by a chamber having an opening in an end and a side wall defined by a plurality of parabolic curved compression grooves and alternate spaced neck members wherein the angle between each of such parabolic curve compression grooves and the neck members increases in said chamber from the opening to the end of said chamber.

Abstract: A fiberglass sucker rod construction is disclosed comprising a cylindrical fiberglass rod having a steel connector member adhesively bonded to each end thereof. The steel connector members are basically identical in their manner of being affixed to each end of the fiberglass rod, each connector member having an internal receptacle defining a series of tapered annular spaces for receiving an epoxy adhesive material which bonds the fiberglass rod in the metal connector member, thereby forming a unitary sucker rod having a male thread connector at one end and a mating female connector at the other end thereof. The epoxy adhesive cures, forming a sleeve having a series of annular tapering surfaces defining annular wedges that are oriented such that tension applied to the rod causes the wedges to be compressed between the rod and connector member, resulting in a radially inwardly directed force to retain the rod in position against such tension.