ISO 6789-2:2017 specifies the method for the calibration of hand torque tools and describes the method of calculation of measurement uncertainties for the calibration.

This document specifies the minimum requirements for the calibration of the torque measurement device where the relative measurement uncertainty interval, W'md, is not already provided by a traceable calibration certificate.

ISO 6789 is applicable for the step by step (static) and continuous (quasi-static) calibration of torque measurement devices, the torque of which is defined by measuring of the elastic form change of a deformable body or a measured variable which is in proportion to the torque.

This document applies to hand torque tools which are classified as indicating torque tools (Type I) and setting torque tools (Type II).

NOTE Hand torque tools covered by this document are the ones identified in ISO 1703:2005 by reference numbers 6 1 00 11 0, 6 1 00 11 1 and 6 1 00 12 0, 6 1 00 12 1 and 6 1 00 14 0, 6 1 00 15 0. ISO 1703 is currently under revision. In the next edition, torque tools will be moved to an own clause, and with this change the reference numbers will also change and additional reference numbers will be added.