Push bending is the most common bending method. The equipment used are universal mechanical or hydraulic press machine, also special pressing curve-making machine. Roll Curve-making devices are commonly used in coiling machine. Three Roller Curve-making determine truth of a circle by three points, continuously curving the slab. Three roller coiling machine has two drive rollers (fixed) and a pressing roller (adjustable). Adjust the vertical position of the pressing rollers to change the relative distance between it and the drive roller. When curve-making, the plate is placed between the drive roller and the pressing roller, the drive roller switching positive and negative direction of rotation, the plate material reciprocate. Adjusting pressing rollers so that gradually depressed, the plate can be bent to the desired curvature of the cylindrical surface, conical surface and smaller curvature hyperbolic. Reduction roller can be lifted at one end, to facilitate the unloading of the workpieces. In addition there are four roll and multi-roll curve-making machine, four roller coiling machine for heavy plate rolling cylinder, four-roll or more multi-roll curve-making machine, with a plurality of pairs of rollers will gradually bent plate into a complicated section surfaces.
For bending parts with higher accuracy requirements, larger radius of curvature and length and less transverse dimensions can be bended on a dedicated curve-making machine. When curve-making, tensile stress acts on all plate thickness, and thus producing only elongation deformation and small deformation after unloading springback, easily ensuring accuracy