The shearing machine of rolling piece in transverse shearing operation is called cold flying shear. It is a kind of processing equipment that can cut iron plate, steel pipe and paper coil quickly. It is a fixed-length shearing machine of metallurgical rolling industry, high-speed wire rod and thread steel. It is a product of modern rolling bar shearing. It has the characteristics of low power consumption and low investment cost.

　　Cold flying shear is often used in steel rolling, paper making and other production lines. In continuous rolling billet workshop or small section workshop, it is placed at the back of the rolling line, cutting the rolled piece into fixed length or only cutting the head and tail. Various types of flying shears are equipped in the cross shearing units, heavy shearing units, galvanizing units and tin plating units of the cold strip workshop. The strip is cut into fixed-length or specified-weight coils. Widespread use of cold flying shear is conducive to the rapid development of rolling production to the direction of high speed and continuity. Therefore, cold flying shear is one of the important links in the development of rolling production.

　　Cold flying shear should ensure good shearing quality - accurate length setting, neat cut surface and a wide range of length adjustment, at the same time, a certain shearing speed. In order to meet the above requirements, the structure and performance of cold flying shear must meet the following requirements in the shearing process:

　　1. The horizontal speed of the cutting edge should be equal to or slightly greater than that of the rolling piece.

　　2. The two blades should have the best clearance.

　　3. In the process of shearing, it is better for the blade to move horizontally, that is, the blade is perpendicular to the surface of the rolled piece.

　　4. Cold flying shears should work according to a certain working system to ensure a fixed length.

　　5. The acceleration and mass stress of the moving component of cold flying shear should be minimized to reduce inertia force and dynamic load.