Fastening screw with polygonal socket for torque introduction with introduction point for torque located inside hollow screw shaft

摘要

The screw has a hollow shaft section (5,7). The torque introduction takes place axially through the hollow at a point, where elastic torsion from the introduction point to the head support, and from the introduction point to the axial center of the supporting thread, are mainly the same. The torque introduction point (t) is longer than normal. The internal diameter of the hollow shaft section is 0,7d. Torque introduction is accord. to Torx (e.g. ISO/DIS 14579).