This standard covers the requirements for electrical rigid steel conduit for use as a raceway for wires or cables of an electrical system. Finished conduit is produced in nominal 10 ft (3.05 m) lengths@ threaded on each end with one coupling attached. It is protected on the exterior surface with a metallic zinc coating or alternate corrosion protection coating (as specified in the 13th edition of UL 6 in Clauses 5.3.3@ 6.2.4@ 7.8 and 7.9) and on the interior surface with a zinc or organic coating. This standard also covers conduit couplings@ elbows@ nipples and conduit lengths other than 10 ft (3.05 m). Properly assembled systems of conduit@ couplings@ elbows and nipples@ manufactured in accordance with this standard@ and other identified fittings provide for the electrical continuity required of an equipment grounding conductor.