Pneumatic Tools for Tightening Threaded Fasteners

This paper outlines the critical factors that must be considered in obtaining good torque control of threaded fasteners when using power tools: torque and tension and control of friction, torque rate, relaxation, multiple fasteners, and measurement errors. The construction of the various pneumatic power tools available to industry today are described, along with their applications. Included are impact wrenches, torque control impact wrenches, screwdrivers, angle wrenches, and assembly machines.