with metric threaded entries, listed conduit fittings
or listed cable fittings
shall be used. Such entries shall be identified
as being metric, or listed adapters
to permit connection to conduit or NPT threaded fittings
shall be provided with the equipment
and shall be used for connection to conduit or NPT threaded fittings
Metric threaded fittings installed into explosionproof or flameproof equipment entries shall have a class of fit of at least 6g/6H and be made up with at least five threads fully engaged.
Informational Note: Threading specifications for metric threaded entries are located in ISO 965-1-2013, ISO general purpose metric screw threads — Tolerances — Part 1: Principles and basic data, and ISO 965-3-2009, ISO general purpose metric screw threads — Tolerances — Part 3: Deviations for constructional screw threads.