Some people may ask, is it not possible to switch directly to domestic bolts when the whole vehicle is made in China? The problem is not that simple. Once the bolt tightening machine of the vehicle assembly line has completed the parameter setting, there are only two possibilities to switch to the domestic bolt when the whole vehicle is made in China:
The domestic bolts can fully meet the existing tightening machine parameter settings without any changes. This is almost impossible. The reason is that the parameters affecting the tightening torque are too many. The domestic bolts need to be in good condition with the foreign bolts. This is not a problem of process stability, but requires complete copying, which is impossible.