Designation system

The designations of most SKF rolling bearings follow a system that may consist of a basic designation with or without one or more prefixes and/or suffixes (→ Basic bearing designation system).
An example and the applicable options for double row deep groove ball bearings are given below.
Basic bearing designation system


4309 ATN9where4309 =Designation 2
A =Designation 3
TN9 =Designation 5
Test Designation 1Prefixes (n. a.)

Test Designation 2Basic designation
Listed in table 1

Catalogue image - Test Designation 3Suffixes - Internal design
ADeviating or modified internal design

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

Catalogue image - Test Designation 5Suffixes - Cage design
TN9Glass fibre reinforced PA66 cage, ball centred

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

Test Designation 6.2Suffixes - Accuracy, clearance, preload, quiet running
C3Radial internal clearance greater than Normal

Catalogue image - Test Designation 6.3Suffixes - Bearing sets, matched bearings (n. a.)

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

Test Designation 6.5Suffixes - Lubrication (n. a.)

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