Bearing Info Page
A lot of information about bearings can be determined from their part number. Most of the bearings that we sell are deep groove ball bearings, which have a four digit part number sometimes followed by a suffix that indicates the type of seal (if any). The first digit is always a six which defines the type of bearing (deep groove ball bearing) The second digit indicates the series/sizing code and the last two digits can be used to determine the bore/inner diameter.
For example, a common bearing is the 6200-ZZ bearing. This bearing part number can be broken down as follows:
6 = type code
2 = series
00 = bore
ZZ = suffix
1 = self-aligning ball bearing
16 = thin section single-row deep groove ball bearing
2 = wide self-aligning ball bearing
22 = self-aligning roller bearing
23 = wide self-aligning roller bearing
3 = double-row angular contact ball bearing
4 = double-row ball bearing
5 = thrust ball bearing
6 = single-row deep groove ball bearing
7 = single-row angular contact bearing
Series (Identifies the relative weight of the bearing):
0 = extra light
1 = extra light thrust
2 = light
3 = medium
4 = heavy
Bore a.k.a. Inner Diameter (in millimeters)
The bore size is figured by multiplying the sum of the third and fourth digits by 5. *** Please note that there are exceptions to this rule discussed below ***
Step 1: add the third and fourth digits together (underlined above).
Step 2: multiply the number that you get from Step 1 by 5.
For this example you should get 20, which is the inner diameter of this bearing in millimeters.
*** Exceptions to the rule ***
For numbers 0 through 3 there is no math required.
00 = 10mm bore
01 = 12mm bore
02 = 15mm bore
03 = 17mm bore
Suffix (Indicates the type of seal)
Z = single side of bearing is sealed with metal
ZZ = both sides of bearing are sealed with metal
RS = single side of bearing is sealed with rubber
2RS = both sides of bearing are sealed with rubber
RZ = bearing side plate lined with low friction synthetic rubber seal
*If there is no suffix the bearing is not sealed on either side
C3 = This marking indicates a radial internal clearance greater than the standard clearance. C3 bearings are usually fitted to equipment where there are large temperature differences between the inner and outer rings, therefore, sufficient clearance is needed to avoid early bearing failure.
x (following the bore) = indicates a special internal design (e.g. x1, x2, x3)