The Basic Bearing Numbering System

Usually, with all the bearings discussed so far, the last two digits of the base bearing number indicate the diameter (size) of the bearing’s bore in millimeters. The first four (4) must be memorized.


  • 00 = 10mm
  • 01 = 12mm
  • 02 = 15mm
  • 03 = 17mm
Bearings Industry

Bore Dimensions


When the last two digits of the base bearing number are 04 or larger, simply multiply the double digit number by five (5) and you have the bore size in millimeters, i.e., 04 = 20mm, 10 = 50mm, and 24 = 120mm. ball bearings.


Angular Contact Ball Bearings

Bearings Industry

Self Aligning Ball Bearings

Bearings Industry

Ball & Roller Thrust Bearings

Bearings Industry

Bearing Series

Ball Bearings

  • 600
  • 6400
  • 6000
  • 6700
  • 6200
  • 6800
  • 6300
  • 6900

Angular Contact Bearing Series

  • 7000
  • 7200
  • 7300

Double Row Angular Contact Bearing Series

  • 3200
  • 5200
  • 3300
  • 5300

Double Row Self Aligning Bearing Series

  • 1200
  • 2200
  • 1300
  • 2300

Thrust Ball Bearing Series

  • 51100
  • 51300
  • 51200
  • 51400