The internal clearance of the bearing is the total distance that one of the bearing rings can move in a radial (radial clearance) or axial (axial clearance) relative to the other bearing ring. The clearance of the bearing before installation is the initial clearance.

Bearing steel is steel used to make balls, rollers and bearing rings. Bearings are subjected to extreme pressure and friction during operation, so bearing steels are required to have high and uniform hardness and wear resistance, as well as high elastic limits.

Rolling bearings are made of bearing steel and heat treated, so rolling bearings not only have high mechanical properties and long service life, but also save the expensive non-ferrous metals used in the manufacture of sliding bearings. Since the rolling bearing has high transmission efficiency and low heat generation, the consumption of lubricating oil can be reduced, and lubrication maintenance is relatively trouble-free.

is there any noise? Hold the inner sleeve of the bearing with your left hand, and turn the outer sleeve with your right hand to make it rotate to hear if it has noise. Since most of the counterfeit products are out of production conditions and completely hand-worked, it is inevitable that impurities such as sand will be incorporated into the bearing body during the production process, so that noise will be generated when rotating. This is the biggest difference between a factory brand that strictly enforces production standards and operates with machines.