The hardness typically refers to the hardness of the working surface of the roller, which is also a primary quality indicator for rollers. It determines the wear resistance of the roller and, to some extent, its service life. The hardness of the roller can be achieved by selecting appropriate materials and applying certain heat treatments to the roller surface. Additionally, for hot-rolled rollers, they should also possess certain heat resistance to ensure the accuracy of the rolled products and, at the same time, determine the service life of the roller.

As rolling technology advances and market competition intensifies, the technical requirements for rolling mill rolls are increasingly stringent. Enhancing the service life of rolling rolls can reduce production costs for products. For roller stands in plate and strip rolling mills, higher requirements are placed on the surface quality of the rolls.

The nominal diameter D of the initial rolling mill and the profile rolling mill, which is both a primary parameter of the mill and a key parameter for roller dimensions, determines the other roller parameters, which are also constrained by strength, rigidity, or structural limitations, once the diameter D is set.

The roller bodies of the initial rolling mill and section rolling mill are of a hollow design, thus, the nominal diameter of the roller should have a precise meaning. Typically, the section rolling mill uses the center distance of the gear base as the nominal diameter of the roller; while the cold rolling mill considers the outer diameter of the roller ring as the nominal diameter.

Therefore, the nominal diameter of perforated roller is always greater than its working diameter. To prevent the hole slots from cutting too deeply, the ratio of the nominal diameter to the working diameter of the roller is generally not greater than 1.4.

The rolling diameter of the roller can be determined based on the bite angle and the strength requirements of the wheel roller.

Calculated roller diameters should be converted to nominal roller diameters in accordance with the national standards for the rigid rolling mill and section rolling mill series. Our initial rolling mill series includes 750, 850, and 1150JL models; the transverse section rolling mills have models such as 4500/300, 4650b, and 4800.