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. It is considered that the variations of the frictional coefficients are caused by the lubricated conditions and so on in the bolt tightening However if the bolt has some configuration errors, the frictional coefficients might be varied by them. In this study, an influence of the squareness error of bolt bearing surface on the clamping force error has been investigated using a simulated experiment. The results showed that the squareness error of bearing surface causes the clamping force error.
