Abstract
In this report, the vibration screw thread tightening method in which low frequency torsional vibration is superposed upon motorwrench tightening with a DC motor is studied. Vibration screw thread tightening characterics are compared with the results of ordinary screw tightening methods (i.e., motorwrench tightening using a DC motor and torquewrench tightening). The main results are as follows : (1) There are three regions during vibration screw thread tightening. (2) The screw thread surface is made smooth by means of the lapping effect of the wear powders produced in screw thread tightening. (3) The vibration screw thread tightening torque coefficient decreased more than the ordinary screw tightening torque coefficient and also decreased in vibration screw thread tightening.
