The integrated bearing is made of high-quality steel. After heat treatment, the hardness can reach 45 ~ 48HRC, which can better resist wear and impact, and prolong the service life of the bearing in the caster. After the shaft and the jacket are assembled into a whole, the installation is convenient, and the bearing can be placed in injection molding. The mandrel is directly injection molded into the wheel, and the wheel and bearing are never separated. You can also add two sealing rings (dust cover) according to customer needs to prevent the penetration of dust, sundries and corrosive liquids, which can run normally in harsh environments.