A straightening machine is an equipment used to straighten metal profiles, bars, pipes, wires, etc. The straightening machine uses straightening rollers to extrude bars and other materials to change their straightness. There are generally two rows of straightening rollers, with varying quantities. There are also two roller straightening machines that rely on the angle changes of the two rollers (concave in the middle, hyperbolic roller) to straighten materials of different diameters. The main types include pressure straightening machines, balance rolling straightening machines, shoe rolling straightening machines, rotary reverse bending straightening machines, and so on.