The setting of bolt tightening torque requires a lot of tests and verification.

The bolt auto-tightening machine is commonly used in modern automobile assembly lines to not only automatically monitor the tightening torque, but also to monitor the number of tightening rings and the angle, in order to prevent safety problems caused by bolt tightening problems. The setting of bolt tightening torque requires a lot of tests and verification. Since a large number of joint ventures in domestic automakers do not master the core technology, this part of the test verification work is basically done abroad. When testing and verifying work abroad, bolts produced abroad are generally used. After all the tests have been verified, it can be used only when it is made in China.