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 SKF deep groove ball bearings are given below.
Example
W 619/6 X-2RS1 where W =
619/6 =
X =
-2RS1 =
Applicable options
Prefixes
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
Basic 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
Suffixes - Internal design
A, AA, C, D Deviating or modified internal design
E Reinforced ball set
Suffixes - External design (seals, snap ring groove, etc.)
N Snap ring groove in the outer ring
NR Snap ring groove in the outer ring, with snap ring
N1 One locating slot (notch) in one outer ring side face
R Flanged outer ring
-RS1, -2RS1 Contact
seal, NBR, on one or both sides
-RS2, -2RS2 Contact seal, FKM, on one or both sides
-RSH, -2RSH Contact seal, NBR, on one or both sides
-RSH2, -2RSH2 Contact seal, FKM, on one or both sides
-RSL, -2RSL Low-friction seal, NBR, on one or both sides
-RST, -2RST Low-friction seal, NBR, on one or both sides
-RZ, -2RZ Non-contact seal, NBR, on one or both sides
-Z, -2Z Shield on one or both sides
-ZNBR Shield on one side, snap ring groove in the outer ring, with snap ring on the same side as the shield
-ZNR Shield on one side, snap ring groove in the outer ring, with snap ring on the opposite side of the shield
-2ZNR Shield 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 dimensions not in accordance with ISO dimension series
Suffixes - Cage design
–
For stainless steel bearings: stamped stainless steel cage, ball centred
For other bearings: stamped steel cage, ball centred
M Machined 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.
TN PA66 cage, ball centred
TN9
Glass fibre reinforced PA66 cage, ball centred
TN9/VG1561 Glass fibre reinforced PA46 cage, ball centred
TNH Glass fibre reinforced PEEK cage, ball centred
Suffixes - Materials,
heat treatment
HA1 Case-hardened inner and outer rings
Suffixes - Accuracy, clearance, preload, quiet running
P5 Dimensional and geometrical tolerances to class P5
P6 Dimensional and geometrical tolerances to class P6
P52 P5 + C2
P62 P6 + C2
P63 P6 + C3
CN Normal 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
C1 Radial internal clearance smaller than C2
C2 Radial internal clearance smaller than Normal
C3 Radial internal clearance greater than Normal
C4 Radial internal clearance greater than C3
C5 Radial internal clearance greater than C4
CA Matched bearing set with small axial internal clearance
GA Matched bearing set with light preload
Suffixes - Bearing sets, matched bearings
DB Two bearings matched for mounting back-to-back
DF Two bearings matched for mounting face-to-face
DT Two bearings matched for mounting in tandem
Suffixes - Stabilization
S0 Bearing rings heat stabilized for operating temperatures ≤ 150 °C (300 °F)
S1 Bearing rings heat stabilized for operating temperatures ≤ 200 °C (390 °F)
Suffixes - Lubrication
GE2
GFJ
GJN
HT
LHT23
LT
LT10
MT33
MT47
VT378
WT
Grease suffixes (table 2)
Suffixes - Other variants
VP311 SKF Food Line bearing:
Blue contact seal made of FDA and EC approved NBR and lubricant (GFJ) registered by NSF as category H1
VQ658 Quiet running properties
