Difference between Thin Section Angular Contact Ball Bearings and Standard  Angular Contact Ball bearings is the cross section dimension were designed to be single, the cross section bearings and standard dimension is unchangeable in a series. It won’t increase with enhance of bore diameter. Therefore, this kinds of thin section bearings were called uniform cross section thin-section bearings. By using the same series of thin-section bearings throughout a products line, the designer could standardize on common components.