The designations of SKF deep groove ball bearings

The designations of SKF deep groove ball bearings follow a SKF bearing designation system that may consist of a basic designation with or without one or more prefixes and/or suffixes.

1	2	3	4	5	/	6.1	6.2	6.3	6.4	6.5	6.6
Prefixes	Basic designation	Suffixes
Prefixes	Basic designation	Internal design	External design	Cage design		Materials, heat treatment	Accuracy, clearance, preload, quiet running	Bearing sets, matched bearings	Stabilization	Lubrication	Other variants

1, 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

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
-RSF, -2RSF: Contact seal, NBR, 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
-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

-: 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

P5: Dimensional and geometrical tolerances (tolerances of run-out and orientation) to class P5
P6: Dimensional and geometrical tolerances (tolerances of run-out) 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
C2: Radial internal clearance smaller than Normal
C3: Radial internal clearance greater than Normal
C4: Radial internal clearance greater than C3
CA: Matched bearing set with small axial internal clearance
GA: Matched bearing set with light preload

S0: Bearing rings heat stabilized for operating temperatures ≤ 150 °C (300 °F)
S1: Bearing rings heat stabilized for operating temperatures ≤ 200 °C (390 °F)

VA947: SKF Food Line bearing made of bearing steel: Blue contact seal made of FDA and EC approved NBR and lubricant (GFM) registered by NSF as category H1
VP311: SKF Food Line bearing made of stainless steel: Blue contact seal made of FDA approved NBR and lubricant (GFJ) registered by NSF as category H1
VQ658: Quiet running properties