Concept
Torque
Definition
The rotational force an endodontic motor applies to a file, set in newton-centimetres (Ncm). The torque limit is the point at which the motor stops driving forward, usually reversing or halting, so a lower limit can protect a fine file from torsional overload while a limit set above what the file carries removes that protection. Manufacturer values differ per file and are listed in each system's instructions for use.