Bearing designation

To identify a bearing, it’s assigned a standardized code referred to as a designation. The designation is made up of one to three parts;

• Prefix
• Basic designation
• Suffix

Prefixes and suffixes, which provide additional information to the designation, are not always included.

The meaning of the numbers and letters that can be included in a designation is listed in the section Code tables below.

Basic designation

A basic designation contains 3-5 digits that always represent these three pieces of information:

• Bearing type,
• Bearing series, and
• Bore size (inner diameter).

Note: the Bearing type and Bearing series put together is called Bearing series.

Let’s take the following three designations as examples

• 626 (3 digit designation)
• 6305 (4 digit designation)
• 62103 (5 digit designation)

626

• The first digit always tells us the Bearing type (6 = Single row deep ball groove bearing.)
• The second digit (2) tells us the Dimension series (2 = Light).
• In a three digit designation, the third digit (6) tells us the Bore size in mm. So in this case, the Bore diameter is 6 mm.

6305

• Again, the first digit tells us the Bearing Type (6 = Single row deep ball groove bearing.)
• The second digit (3) tells us the Bearing series (3 = Medium.)
• The third and fourth digit (05) tells us the Bore size (05 = 25 mm.)

62103

• First digit for Bearing type as always.
• The second and third digit tells us the Dimension series where
  • the second digit (2) is the width code and
  • the third digit (1) is the diameter series
• The fourth and fifth digits (03) tells us the bearing Bore size (03 = 17 mm.)

Prefixes and suffixes

A bearing code can also be made longer to include additional information such as;

• Shield code
• Contact angle code
• Matched pair or stack code
• Internal design code
• External configuration code
• Bearing ring shape code
• Internal clearance code
• Tolerance class code

Code tables

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Additional designation examples

Here are some examples what bearing designations can look like. (What the codes mean is shown under section Code tables below. 6305ZZ