TIGHTENING ERROR PREVENTION METHOD FOR SCREW PART

摘要

PROBLEM TO BE SOLVED: To provide a tightening error prevention method for a screw part limiting the screw part to be tightened per exclusive tool. SOLUTION: At least one recessed part 3 or more are provided on a side face of an engaging part of the screw part with a socket. On the other hand, a projection 4 corresponding to the recessed part 3 is provided on an inner face of a socket of the exclusive tool. This exclusive tool cannot tighten the ordinary screw part because the projection 4 becomes an obstacle and can specify the screw part capable of being tightened. Moreover, this exclusive tool can be used as an exclusive tool capable of managing tightening torque.