ISO International Standard

ISO 5393:2017 specifies a laboratory performance test method for power assembly tools (referred throughout the document as “tool”) for installing threaded fasteners.

ISO 5393:2017 provides a method for the measurement of torque repeatability (scatter)

– over a range of torque rates as specified in this document,

– over a range of torque adjustment as defined by the manufacturer, and

– over a number of operating cycles as defined by the manufacturer.

ISO 5393:2017 provides a method for the measurement of the precision of the built-in torque measurement system for tools incorporating such a feature. See Annex E.

ISO 5393:2017 gives instructions on equipment parameters, what to test for and how to evaluate and present the test data.

ISO 5393:2017 is applicable to tools

– of any power source, e.g. pneumatic, hydraulic, and electric, including battery-powered,

– which apply torque in a generally continuous manner, and

– within the torque range 0,5 Nm to 2 000 Nm. Outside this range, it is acceptable to modify the test method providing that the modification is documented in the test report.

ISO 5393:2017 is not applicable to

– impact or impulse wrenches,

– ratchet wrenches or wrenches with ratcheting clutches, and

– other tools which advance fasteners in discontinuous increments, overcoming static friction at each increment.

ISO 5393:2017 allows a test to be performed at any test torque level; however, in order to minimize the number of test joints necessary for a wide range of test torque levels, a list of preferred test torque levels is provided in Annex A.