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.) |