Bearing Nomenclature 

Suppose you are given a bearing and a code is printed over it and you need to identify the type of bearing by just seeing the code. How would you do it?

Its simple. For eg. You are given a bearing 6206.

  • Here in 6206 bearing its 6 means ‘Single-Row Deep Groove Ball Bearing’

  • 6206 its light type of bearing.

  • In 6206 the last two digits are 06 and bore dia would be 30mm.

The first digit.

 The first digit shows the type of bearing- 
The following are the types of bearings which you could identify:

1 Self-Aligning Ball Bearing 
2 Spherical 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 
8 Felt Seal 

  • R indicates Inch (Non-Metric) Bearing 
  • N indicates Cylindrical Roller Bearing 

Other types of bearing could be found out in broschure of bearing manufacturer.

The second digit
  The second digit tells you about the robustness of the bearing. These series are from lightest to heaviest. 

0 Extra light 
1 Extra light thrust 
2 Light 
3 Medium 
4 Heavy
8 Extra thin section 
9 Very thin section 

And from the last two digits you can get the size of bore dia.
Except the following 0-3 digits the bore dia is last two digits multiplied by 5. 

01 12mm 
02 15mm 
03 17mm 

And for some bearings at last you may find designation like ZZ

Z            – Single shielded 
ZZ          – Double shielded 
RS         – Single sealed 
2RS       – Double sealed 
V            – Single non-contact seal 
VV         – Double non-contact seal 
DDU      – Double contact seals 
NR         – Snap ring and groove 
M           – Brass cage