Designation system

The designations of SKF super-precision bearings follow a system that consists of a basic designation with or without one or more prefixes and/or suffixes.
An example and the applicable options for axial-radial cylindrical roller bearings are listed in the following:
Basic bearing designation system


NRT 260 A/GwhereNRT 260 =
A =
G =

Applicable options for axial-radial cylindrical roller bearings

Test Designation 1
Prefixes (n.a.)

Test Designation 2
Basic designation
NRTAxial-radial cylindrical roller bearing
Bore diameter [mm]

Catalogue image - Test Designation 3
Suffixes - Internal design
ABasic internal design
BModified internal design

Test Designation 4
Suffixes - External design (seals, snap ring groove etc.) (n.a.)

Catalogue image - Test Designation 5
Suffixes - Cage design (n.a.)

Catalogue image - Test Designation 6.1
Suffixes - Materials, heat treatment (n.a.)

Test Designation 6.2
Suffixes - Accuracy, clearance, preload, quiet running (n.a.)

Test Designation 6.4
Suffixes - Stabilization (n.a.)

Suffixes - Lubrication
GBearing greased at the factory

Test Designation 6.6
Suffixes - Other features (n.a.)
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