Bearing Dimensions and Designations for Super Precision Bearings

The dimensions of and designations of super precision bearings (bore, outer diameter, width) are internationally standardised.

Bearing Dimensions

The size of a bearing has to be known for its installation on a shaft and in a housing. This is determined by the dimensions of the outer geometry of the bearing and includes:

  • Diameter of the bearing bore (d)
  • Outer diameter (D)
  • Nominal width (B)
  • Radii (r)
Bearing Designations

The designations of the bearings consist of a combination of numbers and letters. They identify the following parameters:

  • Bearing type
  • Dimensions
  • Dimensional and running accuracy
  • Bearing clearance

The outer dimensions of the rolling bearings are set forth in DIN 616 in accordance with DIN ISO 355. They are designed so that several outer diameters and widths are assigned to each bearing bore to provide a large range of load capacity for bearings with the same bore and design This designation system is also set forth in DIN 623.

1. NIBC High Precision Ball Screw Support Bearing Designation:

2. NIBC High Precision Spindle Bearing Designation:

3. NIBC High Precision Cylindrical Roller Bearing Designation: