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 stainless steel deep groove ball bearings are given below.
Basic bearing designation system


W 619/6 X-2RS1
whereW =Test Designation 1
619/6 =Test Designation 2
X =Test Designation 4
-2RS1 =Test Designation 4
Test Designation 1Prefixes
D/WStainless steel, inch dimensions
WStainless steel, metric dimensions
Stainless steel, metric dimensions, not in accordance with ISO dimension series

Test Designation 2Basic designation
Listed in table 1 or drawing number identification

Catalogue image - Test Designation 3Suffixes - Internal design (n. a.)

Test Designation 4Suffixes - External design (seals, snap ring groove etc.)
Boundary dimensions not in accordance with ISO dimension series
RFlanged outer ring
-2RS1Contact seal, NBR, on both sides
Contact seal, FKM, on both sides
-2RZNon-contact seal, NBR, on both sides
-2TSNon-contact or low-friction seal, PTFE, held in place by a retaining ring, on both sides
-2ZShield on both sides
-2ZSShield on both sides, held in place by a retaining ring

Catalogue image - Test Designation 5Suffixes - Cage design

Stamped stainless steel cage, ball centred
Glass fibre reinforced PA66 cage, ball centred

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

Test Designation 6.2Suffixes - Accuracy, clearance, preload, quiet running
Dimensional and running accuracy to P5 tolerance class
Dimensional and running accuracy to P6 tolerance class
Radial 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

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

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

Test Designation 6.5Suffixes - Lubrication
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

SKF logo