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 high-capacity cylindrical roller bearings are given below.
Basic bearing designation system


NCF 2340 ECJB/PEXwhereNCF 2340 =
EC =
JB =
Test Designation 1Prefixes
LSeparate inner or outer ring of a separable bearing
Inner or outer ring with roller and cage assembly of a separable bearing

Test Designation 2Basic designation
Listed in table 1

Catalogue image - Test Designation 3Suffixes - Internal design
ECOptimized internal design incorporating more and/or larger rollers and with modified roller end / flange contact

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

Catalogue image - Test Designation 5Suffixes - Cage design
JASheet steel cage, outer ring centred
Sheet steel cage, inner ring centred
MHMachined brass cage, inner ring raceway centred

Catalogue image - Test Designation 6.1Suffixes - Materials, heat treatment
L4BBearing rings and rollers black oxidized
L5BRollers black oxidized
L7BInner ring and rollers black oxidized

Test Designation 6.2Suffixes - Accuracy, clearance, preload, quiet running
CNNormal radial internal clearance; only used together with an additional letter that identifies a reduced or displaced clearance range
  • H = Reduced clearance range corresponding to the upper half of the actual clearance range
  • L = Reduced clearance range corresponding to the lower half of the actual clearance range
  • M = Reduced clearance range corresponding to the middle half of the actual clearance range
The above letters are also used together with the clearance classes C2, C3, C4 and C5, e.g. C2H.
C2Radial internal clearance smaller than Normal
C3Radial internal clearance greater than Normal
C4Radial internal clearance greater than C3
C5Radial internal clearance greater than C4

Catalogue image - Test Designation 6.3Suffixes - Bearing sets, matched bearings
DRSet of two matched bearings
TRSet of three matched bearings
QRSet of four matched bearings

Test Designation 6.4Suffixes - Stabilization
S1Bearing rings heat stabilized for operating temperatures ≤ 200 °C (390 °F)

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

Test Designation 6.6Suffixes - Other variants
SKF Explorer bearing, used only when same-sized conventional and SKF Explorer bearings are available
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