I have a basic understanding of bearing designation, but I may not be able to provide an exhaustive or deeply technical explanation. Here are the key points about bearing designations:
Bearings are designated by letters and numbers that provide information about the bearing type, size, and options. The designation consists of letters that indicate the bearing type (like B for ball bearing), numbers that specify dimensions like bore diameter and outer diameter, and sometimes additional letters for special features.
The bearing type letters are:
B – Ball bearing
C – Cylindrical roller bearing
T – Tapered roller bearing
S – Spherical roller bearing
The dimensions are specified in millimeters. For example, 206 refers to a 20 mm bore and 60 mm outer diameter.
Optional letters can indicate things like:
O – Seal
M – Metric designation
E – Open type
RL – Grease lubricated
LL – Lithium grease lubricated
SH – Pre-greased – deep groove ball bearing
W – Wide inner ring
Common examples:
6203 – Ball bearing, 20mm bore, 40mm outer dia.
6003 M – Metric ball bearing, 20mm bore, 40mm outer dia.
6202E – Open ball bearing, 20mm bore, 40mm outer dia.
6301 SH – Pre-greased deep groove ball bearing, 30mm bore, 50mm outer dia.
There are more customized and specialized designations for larger, higher load, precision, etc. bearings.