[Technical Information] Basic Knowledge of Understanding Looseness: Proper Tightening of Screws

When tightening bolts, it is important to select the appropriate strength class and friction coefficient that match the target bolt axial force!

To perform safe screw fastening, sufficient initial tightening force F is required, and for that, it is necessary to tighten with an appropriate tightening torque T. The characteristics of the fastening methods for screw fasteners can be broadly divided into two categories: elastic region tightening and plastic region tightening. Therefore, when tightening bolts, it is important to select the strength classification (yield stress) and friction coefficient that correspond to the target bolt axial force. Thus, to perform appropriate screw tightening, it can be said that it is essential to have a good understanding of the friction coefficient, which significantly affects the tightening torque and initial tightening force. 【Fastening Methods for Screw Fasteners】 ■ Elastic Region Tightening: Tightening within the range where the bolt does not yield ■ Plastic Region Tightening: Tightening within the range where the bolt yields and reaches the ultimate tightening axial force *For more details, please refer to the PDF document or feel free to contact us.

Work tools