1) The nut is screwed perpendicularly to the axis of the screw, do not tilt;

2) During the tightening process, the force must be uniform, and the force must not exceed the safe torque value;

3) Use torque wrenches or socket wrenches as much as possible, and avoid using adjustable wrenches or electric wrenches;

4) Cool down when using under high temperature, and do not rotate quickly when using, so as to avoid the rapid rise of temperature and cause lockup (such as electric wrench, etc.).