Abstract
In a bolt tightening, it is well known that the cause of tightening error of the torque control method is a variation of the frictional coefficients of thread surfaces and bearing surfaces. In this study, an influence of the squareness error of bolt bearing surface on the clamping force error has been investigated. The results showed that the squareness error of bearing surface causes the clamping force error. The results also showed that the clamping force error increased with an increase in the squareness error.
