A bearing designation is three pieces of information in one string: the type and dimension series, the bore size, and the suffixes that define how it is built. Reading it correctly is the difference between ordering a bearing and ordering the right bearing.
| Part | Example | Meaning |
|---|---|---|
| Type | 6 | Deep groove ball bearing |
| Dimension series | 2 | Light series (width and diameter) |
| Bore code | 05 | 05 × 5 = 25 mm bore |
| Seal suffix | 2RS1 | Contact rubber seal, both sides |
| Clearance suffix | C3 | Radial internal clearance greater than normal |
| Precision suffix | P5 | Tolerance class 5 |
| Cage suffix | TN9 | Moulded polyamide cage |
| Special suffix | /S1 | Heat stabilised to 200 °C |
For bore codes 04 to 96, multiply by 5: 04 = 20 mm, 05 = 25 mm, 12 = 60 mm, 96 = 480 mm. Three exceptions: 00 = 10 mm, 01 = 12 mm, 02 = 15 mm, 03 = 17 mm. Below 10 mm the bore is written directly, as in 608 (8 mm) or 623 (3 mm).
| Group | Suffixes | Effect |
|---|---|---|
| Seal | Z, 2Z, RS, 2RS, 2RS1, 2RZ, RSH | Protection, friction and speed rating |
| Clearance | C2, CN, C3, C4, C5 | Internal play after fit and heat |
| Precision | P6, P6X, P5, P4, P2 | Runout and tolerance class |
| Cage | J, M, TN9, T, TVP | Material and speed/temperature limits |
| Heat stabilisation | S0, S1, S2 | Dimensional stability at temperature |
| Grease | GJN, VT378 and maker codes | Fill type and quantity |
The designation does not tell you the load rating, the limiting speed, the grease quantity or the cage unless a suffix says so. Those live in the catalogue for that specific size and maker. Two bearings with identical designations from different makers can differ in cage and grease, which is why cross-brand substitution needs the suffix checked rather than assumed.
A deep groove ball bearing, light dimension series, 25 mm bore. The 6 is the type, 2 the series, 05 the bore code (5 × 5 = 25 mm).
Radial internal clearance greater than normal, used where fits and heat would otherwise close a CN bearing. It is the standard clearance for motors.
Nothing in practice. Both mean a steel shield on both sides; European catalogues write 2Z, Japanese and Chinese catalogues write ZZ.
Inch bearings use a different system, often a two-part number with the bore and OD in sixteenths or a manufacturer code. Send the number and we will decode it against the catalogue.
Send the model list and quantities — we reply with brand options, price and lead time within 30 minutes on working days.