This International Standard specifies requirements for conduit and cable fittings including cast metal boxes and conduit bodies used with extra-heavy duty electrical rigid steel (EHDERS) conduit conforming to IEC 60981. This edition constitutes a technical revision. It incorporates numerous additional tables which are significant changes to the first edition including: revision and update; new requirements necessitated by the proliferation of communication cables used in connection with EHDERS conduits and fittings