Straightening machine is the equipment for straightening metal profiles, bars, pipes, wires, etc. The straightening machine changes the straightness by squeezing the bar and so on with the straightening roller. Generally there are two rows of straightening rollers, the number varies. There are also two-roll straighteners that rely on the Angle changes of the two rollers (concave in the middle, hyperbolic rollers) to straighten materials of different diameters.