Abstract: An electrical conduit piece of the invention has two external threaded regions, one threaded region having a left hand threaded region and one having a right hand threaded region. This conduit piece is particularly well adapted to be used in conventional conduit systems by coupling two conventional conduit pieces through a coupling of the invention having two internal threaded regions, one threaded region having left hand threads and the other threaded region having right hand threads. A groove may be formed in the internal wall of the coupling, e.g., at or near its longitudinal center to provide an open region in which ends of conduit pieces inserted into the coupling can abut. Residing in the grooved region of the coupling is a locking ring which scores the threads of the conduit pieces at 90° preventing any tangential force from outside of the system from unscrewing one of the conduit pieces from the coupling. In a preferred embodiment, the conduit piece is embodied as a curved or elbow conduit.