The main working components and tools on the mill that produce continuous plastic deformation of the metal. The roll is mainly composed of a roll body, a roll neck and a shaft head. The roll body is the middle part of the roll that actually participates in the rolling of the metal. It has a smooth cylindrical or grooved surface. The roll neck is mounted in the bearing and the rolling force is transmitted to the frame through the bearing housing and the pressing device. The transmission end shaft head is connected to the gear base through the connecting shaft, and transmits the rotational torque of the motor to the roller. The rolls can be arranged in the form of two rolls, three rolls, four rolls or multiple rolls in the rolling mill stand.