The accuracy is divided into P0, P6, P5, P4, P2 from low to high. P2 is the highest precision class used in aerospace, P4 is the second highest precision class used in precision machine tools, and P0 is the general class.

 

 

 

Standard level of accuracy

 

 

 

The standard accuracy grade of bearings is 0, 6X, 6, 5, 4 and 2.

 

 

 

Bearing accuracy is improved from grade 0 in turn. For general purposes, grade 0 is enough to meet the demand, but in some high-precision conditions or occasions, grade 5 or higher accuracy is required. Although the accuracy level is based on ISO standards, it is limited to the domestic market. Relative to abroad, the name of each country to the product and measure standard are different.

 

 

 

The tolerance grade of the bearing is mainly determined according to the rotation accuracy requirement of the shaft to the support.

 

 

 

Class 0: widely used in general bearing systems with rotation accuracy greater than 10um. Such as ordinary machine tool speed mechanism, feed mechanism, variable speed mechanism of cars, tractors, ordinary motors, water pumps and agricultural machinery and other general machinery in the rotating mechanism.

 

 

 

Level 2: in the ultra-precision equipment with rotation accuracy less than 5um or high speed, such as precision coordinate boring machine, precision grinding machine gear system, precision instruments, meters and high-speed cameras and other precision systems.

 

 

 

Grade 5: in the precision bearing system with rotation accuracy of 5-10um or higher speed, such as bearings used in ordinary lathes (front support with grade 5, rear support with grade 6) more precise instruments and meters, as well as precision instruments and meters, and precision rotating mechanism.