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 four-point contact ball bearings are given below.
Example
| QJ 318 N2PHAS | where | QJ 318 = |  |
| N2 = |  |
| PHAS = |  |
 | Prefixes (n.a.)
|
| Basic designation |
| Listed in table 1 |
 | Suffixes - Internal design (n.a.) |
| Suffixes - External design (seals, snap ring groove etc.) |
| N2 | Two locating slots (notches) in one outer ring side face, 180° apart |
| Suffixes - Cage design |
| FA | Machined steel cage, outer ring centred |
| MA | Machined brass cage, outer ring centred.
|
| PHAS | Glass fibre reinforced PEEK cage, with lubrication grooves in the guiding surface, outer ring centred |
 | Suffixes - Materials, heat treatment (n.a.)
|
 | Suffixes - Accuracy, clearance, preload, quiet running |
| P6 | Dimensional and geometrical tolerances to class P6
|
| P62 | P6 + C2 |
| P63 | P6 + C3 |
| P64 | P6 + C4 |
P6CNL
| P6 + CNL
|
CNL
| Axial internal clearance in the lower half of the Normal range
|
| C2 | Axial internal clearance smaller than Normal |
| C2H | Axial internal clearance in the upper half of the C2 range
|
| C2L | Axial internal clearance in the lower half of the C2 range
|
| C3 | Axial internal clearance greater than Normal |
| C4 | Axial internal clearance greater than C3 |
344524
| C2H + CNL
|
 | Suffixes - Bearing sets, matched bearings (n.a.) |
 | Suffixes - Stabilization |
S1
| Bearing rings heat stabilized for operating temperatures ≤ 200 °C (390 °F)
|
 | Suffixes - Lubrication (n.a.) |
 | Suffixes - Other variants
|
| 309829 | Larger balls
|
