Abstract: A power thread comprising a tubing or casing connection having a collar threadably connected to a tubular member at each end is disclosed, utilizing a shallow tapered thread with relatively low crest height. The device has a number of closely mated threads adjacent the inserted end of the tubular member and diminishing but still load bearing engagement of the remaining threads. In one example of a five thread buttress according to the invention, the root to crest dimension of the thread profile is about 0.040" and the thread profile has a taper of about 0.040" per inch. The load flank side of the thread on the tubular member and coupling has about a 3.degree. angle and the stab flank side of the thread has about a 10.degree. angle, relative to a plane perpendicular to the central axis. The crest surface of the threads on the collar and tubular member have a taper of about 1.75.degree. from the approximate midregion of the crest surface to the stab flank.