TAPPING SCREW FOR SYNTHETIC RESIN AND SYNTHETIC RESIN PRODUCT USING THE TAPPIN SCREW

摘要

PROBLEM TO BE SOLVED: To reduce the waste amount of a synthetic resin medium by preventing a screw from loosening by using a large clamping force, preventing the clamping force from lowering by increasing internal thread breaking torque several-times greater than driving torque, and securely refastening the synthetic resin medium as to a synthetic tapping screw and a synthetic resin product using the tapping screw. SOLUTION: Internal thread holes 3a, 3b, 3c; 3d; 3e, and 3f formed in a member to be fastened are set at 70% to 93% in the sectional area of an outer diameter D1 of a external screw part 4 of the synthetic resin tapping screw screwed in the internal thread hole so as to exactly carry out the refastening of the member to be fastened without generating the loosening.