SKF bearing designation system
An SKF bearing number is made up of a prefix, basic designation and suffix. The basic designation tells you the bearing type, diameter/width series and bore size. Prefixes and suffixes describe cages, seals, internal clearance, tolerance and special features.
Basic designation of SKF bearing
The basic designation combines the bearing series code and the bore code. The table below shows the most common SKF bearing series symbols.
| Bearing type | Series symbol |
| Double row angular contact ball bearing | 32, 33, 52, 53 |
| Self-aligning ball bearing | 12, 13, 22, 23 |
| Spherical roller bearing | 213, 222, 223, 230, 231, 232, 240, 241 |
| Tapered roller bearing | 302, 303, 313, 320, 322, 323, 329, 331, 332 |
| Thrust ball bearing | 511, 512, 513, 514 |
| Deep groove ball bearing (single row) | 60, 62, 63, 64, 68, 69 |
| Angular contact ball bearing (single row) | 70, 72, 73 |
| Cylindrical roller thrust bearing | 811, 812 |
| CARB toroidal roller bearing | C |
| Cylindrical roller bearing (single row) | N, NU, NJ, NUP, NF |
| Cylindrical roller bearing (double row) | NN, NNU, NNCF |
| Four point contact ball bearing | QJ |
Bore code
For bore diameters from 10 mm to 480 mm the bore code is the bore diameter divided by 5. Special codes apply for small bores: 00 = 10 mm, 01 = 12 mm, 02 = 15 mm, 03 = 17 mm. Bores smaller than 10 mm or larger than 480 mm are stated directly in the designation.
Common SKF suffixes
| Suffix | Meaning |
| Z / 2Z | Pressed steel shield, one or both sides |
| RS1 / 2RS1 | Contact seal of NBR with sheet steel reinforcement, one or both sides |
| RZ / 2RZ | Non-contact seal of NBR, one or both sides |
| RSL / RSH | Low-friction (RSL) or contact (RSH) NBR seal |
| C2 / C3 / C4 / C5 | Radial internal clearance smaller (C2) or greater (C3–C5) than normal |
| P6 / P5 / P4 | Dimensional and running accuracy to ISO tolerance class 6, 5 or 4 |
| M / MA / MB | Machined brass cage, outer-ring (MA) or inner-ring (MB) guided |
| J / TN9 | Pressed steel cage (J) or glass fibre reinforced PA66 cage (TN9) |
| K / K30 | Tapered bore, taper 1:12 or 1:30 |
| DB / DF / DT | Matched pair: back-to-back, face-to-face or tandem |
| S1 / S2 | Heat stabilized for operating temperatures up to 200 °C / 250 °C |
| W33 / W20 | Lubrication groove and holes in outer ring (W33) or three holes (W20) |