A Study on Bolt Axial Tension Control by the Calibrated Wrench Method : 1st Report, Distribution of Bolt Axial Tension

Abstract

For tightening bolted joints, the calibrated wrench method is widely used in practice. In this method the axial tension of a bolt is controled by measuring the wrench torque. However the method is not so accurate since the measurement of axial tension is indirect. In this paper, the statistical distribution of the magnitude of the axial tension in bolts, which were tightened by the calibrated wrench method, was formulated. As an example, the distribution of axial tension was shown for a metric fine screw.