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 alignment needle roller bearings are given below.
Example
| RPNA 15/28
| where | R = |  |
| PNA 15/28 = |  |
| Prefixes
|
| R
| Bearing without an inner ring |
|
| Basic designation (table 1) |
| PNA
| Alignment needle roller bearing |
| Suffixes - Internal design (n.a.) |
 | Suffixes - External design (seals, snap ring groove etc.) (n.a.) |
| Suffixes - Cage design (n.a.) |
| Suffixes - Materials, heat treatment (n.a.) |
 | Suffixes - Accuracy, clearance, preload, quiet running |
| C2 | Radial internal clearance smaller than Normal |
| C3 | Radial internal clearance greater than Normal |
| C4 | Radial internal clearance greater than C3 |
| Suffixes - Bearing sets, matched bearings (n.a.) |
 | Suffixes - Stabilization (n.a.) |
 | Suffixes - Lubrication (n.a.) |
| Suffixes - Other variants (n.a.) |
