Standards Development

Scope

This document specifies a laboratory performance test method for power assembly tools (referred throughout the document as “tools”) for installing threaded fasteners.

It 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;

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

It gives instructions on equipment parameters, what to test for and how to evaluate and present the test data.

It is applicable to tools

— of any power source, such as pneumatic or electric, including battery-powered,

— which apply torque in discontinuous increments,

— within the torque range 0,5 N·m to 800 N·m. Outside this range, it is acceptable to modify the test method providing that the modification is documented in the test report.

It is not applicable to:

— impact wrenches;

— ratchet wrenches or wrenches with ratcheting clutches.

The relationship between torque measurements and tension-based tests is commented on in Informative Annex A.

The use of tools using discontinuous operation of the motor to provide torque impulses is discussed in Informative Annex B.

It requires manufacturers to perform tests over their defined torque range of the tool; however, it allows users to perform single point tests 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 informative Annex C.