In the high speed rolling process, rod coils easily are out of mill roll, the rod coils is very dangerous, because it is very hot and high speed. Therefore, the guide must be fixed accurately to mill roll, which guide rollers axis and roll center must be exactly one line. Only in this way there will be less possibility of removing. High speed is to be efficient, but high speed of guide roller has reached bearing limit and the guide roller easily is failure due to pitting corrosion, so this two parts are wearing parts. When guide must frequently be replaced, rolling system must be stopped, but that led to reduce efficiency. Therefore guide rollers axis and roll center must be exactly one line to reduce pressure of guide roller bearing and guide roller and times to replace guide frequently.

The guide Replacement must be fast and accurate. This process includes an off-line and an on-line. An off-line guide corrector is used to correct space between two guide rollers and position between guide rollers axis and guide seat, a guide that has corrected is spare. An on-line guide corrector is used to correct position between mill rolls axis and guide seat, then guide plate must be fixed. When there is a damaged guide, rolling system must be stopped, the damaged guide can be changed by a corrected guide quickly, this way can reduce downtime.