Difference between three roll and four roll

　　There are three roll bending machine and four roll plate bending machine. It is a kind of general equipment for bending metal plate into cylinder, arc or other shapes. It has the advantages of simple structure, light weight, easy to manufacture and repair, and low investment. This function is widely used in creation, boiler steam, chemical industry, nonmetal structure and machine building.

　　The three roll and four roll bending machines have the functions of rolling O-type, U-shaped and multi-stage R-shaped plates. According to the principle of three-point rounding, the plastic deformation of the sheet metal is caused by the change of the relative orientation and rotation of the workpiece, so as to obtain the workpiece with predetermined shape. Because of its simple structure, reliable function and low cost, it has been widely used in boiler, shipbuilding, petroleum, carpenter, metal structure and other mechanical manufacturing profession.