In terms of grade, bearing steel balls have many precisions. According to the grade list in the standard GB/T308-2002, they are divided into G5, G10, G16, G28, G40, G60, G100, G200, G500, G1000, etc. G is the letter of Grade in English. The numbers that follow have different levels. The smaller the number, the higher the accuracy and the better the steel ball. High-precision ones are generally used in precision machinery, auto parts, aerospace and other industries with higher requirements, and low-precision ones are generally used in industries such as grinding, crushing, and mixing.