Abstract: A method for making a riser component includes: positioning a coupler adjacent and end of a tube such that a region of the coupler forms an interface with the tube's end, wherein the region includes a material (in some embodiments an aluminum alloy), and the tube's end includes a groove and another material (in some embodiments a steel alloy) that is different than the region's material; heating the region of the coupler to increase the region's malleability; and exerting pressure on the region of the coupler to plastically deform the region to insert some of the region's material into the groove in the tube's end. By fixing the coupler to the tube in this manner, the coupler may be strongly secured to the tube, and thus able to withstand high, dynamic loads frequently experienced in service. Also, the material of the coupler may be different than the material of the tube, and thus the material of the coupler may be lighter than the material of the tube.

Abstract: A method for making a riser component includes: positioning a coupler adjacent and end of a tube such that a region of the coupler forms an interface with the tube's end, wherein the region includes a material (in some embodiments an aluminum alloy), and the tube's end includes a groove and another material (in some embodiments a steel alloy) that is different than the region's material; heating the region of the coupler to increase the region's malleability; and exerting pressure on the region of the coupler to plastically deform the region to insert some of the region's material into the groove in the tube's end. By fixing the coupler to the tube in this manner, the coupler may be strongly secured to the tube, and thus able to withstand high, dynamic loads frequently experienced in service. Also, the material of the coupler may be different than the material of the tube, and thus the material of the coupler may be lighter than the material of the tube.

Abstract: A locking nut for use with a bolt for connecting members together. The bolt has a head and a shank. The members are disposed between the head and the nut when the locking nut connects the members together. At least a portion of the shank has external threads formed thereon. The locking nut includes a shell having a bore extending therethrough for receiving the bolt. At least a portion of a wall of the bore has internal threads formed thereon. The shell is sized and shaped to permit rotation of the nut on the bolt for tightening the nut on the bolt. The nut further includes a generally tubular insert sized for being received in the bore of the shell. The insert has a threaded portion having an outer surface with external threads for threaded engagement with the internal threads of the shell, and an inner surface with internal threads for threaded engagement with the external threads of the bolt. The insert includes a locking portion constructed for interlocking the insert with the shell.