SKF matched single row angular contact balls are available in 72XX and 73XX series, and the standard accuracy of the bearing is P6 (not marked in the bearing model), they can be assembled in a back-to-back form or a face-to-face form. Their suffix meanings: {TodayHot}B - 40°; E - high load carrying capacity; CB/GA - clearance/preload SKF has 3 clearance grades: CB - standard axial clearance, paired bearing installation; CC - Axial clearance is less than CB; CA - Axial clearance is less than CCSKF and there are 3 preload grades: GA - light preload; GB - preload greater than GA; GC - preload greater than GB; Cage type: SKF provides two types of cage bearings used in petrochemical industry centrifugal pumps. Machined brass cage (denoted by M) and hammered steel cage (denoted by J). On the contrary, the use of plastic cage bearings is strictly prohibited. Here we choose angular contact ball bearings with the suffix BECBM for use in centrifugal pumps for the petrochemical industry. This is not only because less internal bearing clearance (CB rating) after assembly can well control rolling element sliding in the bearing, but the machined brass cage is stronger than the slamming steel cage design and has higher work reliability. Because of this, many petrochemical companies are using bearings with the suffix BECBM as their standard bearings.