There are several ways to fasten the bolts:
① Torque fixing method: Its working principle is that there is a large relationship between the size of the torque and the axial pretightening force. This fixing method is easy to operate and intuitive in image, and is adopted by people at this stage.
②Corner fixing method: The direction of rotation corresponds roughly to the sum of the screw shape variable and the amount of loosening of the tightened part, so the predetermined tightening force is usually achieved in accordance with the specified rotation direction.
③Strength limit fixing method: The purpose of the basic theory is to tighten the screw to the limit point of bending strength