Bearing Code Reference

Symbols of Bearings

Bearing numbering is important to make sure that the bearing type and the bearing technical properties are expressed properly.Ordering a wrong part for the production environments can be detrimental, i.e. delays in a production environment due to ordering wrong bearing part number will lead to loss of time and money.

In order to prevent errors in coding of 100,000 different bearing types all around the world, bearings are systematically coded. With this coding system, every bearing has its own symbol.

Criteria for bearing symbols:

1. Bearing Type
2. Bearing Dimensions
3. Bearing Tolerances
4. Bearing Internal Clearance
5. Other technical details

Note: Ball bearing coding is based on DIN 623 standard.


Prefixes and Suffixes

If the bearing has a shield or seal, or internal clearance is larger than normal, or any other property that is not normal, then the property is denoted by either with a prefix or a suffix.

Some prefixes and suffixes used at ORS are provided below. These prefixes and suffixes may differ between different bearing suppliers.


Ball Bearings


Suffix Instructions


Cylindrical Roller Bearings

Cylindrical roller bearings are classified based on the existence of shoulders on the rings. Information about our current production is provided below.


Tapered Roller Bearings

Inch and metric types are coding systems differ from each other. In addition, the coding is also different under ISO 355.

AFBMA inch part numbering ;

ISO dimensional metric numbering ;

Metric numbering according to ISO 355 ;