In last videos, we learned the basic code of bearings, which represent standard bearings. When there are changes in the structural shape, dimension, tolerance, technical requirements, etc. of the bearing, it is necessary to supplement the basic code with the prefix code and the suffix code.
In this video, let’s learn about the prefix code of bearing code. The prefix code is represented by letters and is used to indicate bearing subunit. The common prefix code includes: L, which refers to the separable inner or outer ring of separable bearing, such as LN 207, which represents the outer ring of N 207; R, which refers to the subunit without separable inner or outer ring, such as RNU 207, which represents outer ring and roller assembly of NU 207; K, which refers to roller and cage assembly, such as K 81107, representing 81107 without inner and outer ring; WS, which refers to the thrust cylindrical roller bearing shaft washer, such as WS 81107; GS, which refers to the thrust cylindrical roller bearing housing washer, such as GS 81107; F, which refers to radial ball bearing with flanged outer ring (only apply to d ≤ 10mm), such as F 618/4; FSN, which refers to separable miniature angular contact ball bearing with flange outer ring (only apply to d ≤ 10mm), such as FSN 719/5-Z; KIW-, which refers to thrust bearing assembly without housing washer, such as KIW-51108; KOW-, which refers to thrust bearing assembly without shaft washer, such as KOW-51108. The specific meanings and examples of prefix codes are summarized in the chart.