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 needle roller and cage assemblies are given below.
Basic bearing designation system


K 32x40x42 ZWTNwhereK 32x40x42 =
ZW =
TN =

Test Designation 1
  Prefixes (n.a.)

Test Designation 2
Basic designation
KNeedle roller and cage assembly

Catalogue image - Test Designation 3
Suffixes - Internal design
DDeviating or modified internal design with the same boundary dimensions. Generally dropped after a certain changeover period, but may have the significance to bound to the particular bearing design/series.
Example: K 40x45x17 D
(Double split cage)
DSSingle split needle roller and cage assembly

Test Designation 4
Suffixes - External design (seals, snap ring groove etc.)
ZWDouble row needle roller and cage assembly (double row cage)

Catalogue image - Test Designation 5
Suffixes - Cage design
TNGlass fibre reinforced PA66 cage

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

Test Designation 6.2
Suffixes - Accuracy, clearance, preload, quiet running
/SORT..Tolerance grade of needle rollers of a needle roller and cage assembly, the numbers following identify the actual limits in μm, e.g. /SORT-2-4

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

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

Suffixes - Lubrication (n.a.)

Test Designation 6.6
Suffixes - Other variants
VG052Single split PES (polyethersulfone) cage
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