Use the Conduit Locknuts to secure RIGID and IMC conduit and various threaded fittings to steel outlet boxes and other metal enclosures. Zinc plated for corrosion resistance. These conduit locknuts can be used for outdoor applications. Indoor and outdoor use. Zinc-plated steel for corrosion resistance. Exceeds UL 514B safety requirements. Designed to cut through protective coatings on boxes and enclosures to assure ground continuity.