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).
Examples and the applicable options for SKF deep groove ball bearings are given below.
Basic bearing designation system

Examples

W 619/6 X-2RS1
whereW =
619/6 =
X =
-2RS1 =
Test Designation 1Prefixes
D/W
Stainless steel, inch dimensions
ICOS-Oil sealed bearing unit
W
Stainless steel, metric dimensions
WBB1
Stainless steel, metric dimensions, not in accordance with ISO dimension series

Test Designation 2Basic designation
Listed in table 1
2..
Single row bearing with filling slots in the 02 dimension series
3..
Single row bearing with filling slots in the 03 dimension series
EE, EEB, R, RLS, RMS
Inch bearing
Bearing size for inch bearings
2
to
40
(/8) 1/4 in. (6,35 mm) bore diameter

(/8) 5 in. (127 mm) bore diameter

Catalogue image - Test Designation 3Suffixes - Internal design
A, AA, C, DDeviating or modified internal design
EReinforced ball set

Test Designation 4Suffixes - External design (seals, snap ring groove etc.)
NSnap ring groove in the outer ring
NRSnap ring groove in the outer ring, with snap ring
N1One locating slot (notch) in one outer ring side face
R
Flanged outer ring
-RS1, -2RS1Contact seal, NBR, on one or both sides
-RS2, -2RS2Contact seal, FKM, on one or both sides
-RSH, -2RSHContact seal, NBR, on one or both sides
-RSH2, -2RSH2Contact seal, FKM, on one or both sides
-RSL, -2RSLLow-friction seal, NBR, on one or both sides
-RST, -2RST
Low-friction seal, NBR, on one or both sides
-RZ, -2RZNon-contact seal, NBR, on one or both sides
-Z, -2ZShield on one or both sides
-ZNBRShield on one side, snap ring groove in the outer ring, with snap ring on the same side as the shield
-ZNRShield on one side, snap ring groove in the outer ring, with snap ring on the opposite side of the shield
-2ZNRShield on both sides, snap ring groove in the outer ring, with snap ring
-2ZS
Shield on both sides, held in place by a retaining ring
X
Boundary dimension not in accordance with ISO dimension series

Catalogue image - Test Designation 5Suffixes - Cage design
  • For stainless steel bearings: stamped stainless steel cage, ball centred
  • For other bearings: stamped steel cage, ball centred
MMachined brass cage, ball centred; different designs or material grades are identified by a number following the M, e.g. M2
MA(S)Machined brass cage, outer ring centred. The S indicates a lubrication groove in the guiding surface.
MB(S)Machined brass cage, inner ring centred. The S indicates a lubrication groove in the guiding surface.
TNPA66 cage, ball centred
TN9Glass fibre reinforced PA66 cage, ball centred
TN9/VG1561Glass fibre reinforced PA46 cage, ball centred
TNHGlass fibre reinforced PEEK cage, ball centred

Catalogue image - Test Designation 6.1Suffixes - Materials, heat treatment
HA1Case-hardened inner and outer rings

Test Designation 6.2Suffixes - Accuracy, clearance, preload, quiet running
P5Dimensional and running tolerances to class P5
P6Dimensional and running tolerances to class P6
P52P5 + C2
P62P6 + C2
P63P6 + C3
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
  • P = Displaced clearance range comprising the upper half of the actual clearance range plus the lower half of the next larger clearance range
The above letters are also used together with the clearance classes C2, C3, C4 and C5, e.g. C2H
C1Radial internal clearance smaller than C2
C2Radial internal clearance smaller than Normal
C3Radial internal clearance greater than Normal
C4Radial internal clearance greater than C3
C5Radial internal clearance greater than C4
CAMatched bearing set with small axial internal clearance
GAMatched bearing set with light preload

Catalogue image - Test Designation 6.3Suffixes - Bearing sets, matched bearings
DBTwo bearings matched for mounting back-to-back
DFTwo bearings matched for mounting face-to-face
DTTwo bearings matched for mounting in tandem

Test Designation 6.4Suffixes - Stabilization
S0Bearing rings heat stabilized for operating temperatures ≤ 150 °C (300 °F)
S1Bearing rings heat stabilized for operating temperatures ≤ 200 °C (390 °F)

Test Designation 6.5Suffixes - Lubrication
GJN
HT
LHT23
LT
LT10
MT33
MT47
VT378
WT
Grease suffixes (table 2)

Test Designation 6.6Suffixes - Other variants
VP311SKF Food Line bearing: Blue-coloured contact seal made of FDA and EC approved NBR and lubricant (GFJ) registered by NSF as category H1
VQ658Quiet running properties
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