6908 Bearing
Bore (d) 40 mm
Outside diameter (D) 62 mm
Width (B) 12 mm
Inches (bore × OD × width) 1.5748 × 2.4409 × 0.4724″
Deep-groove ball bearing, thin section (6900) series. Seal/shield suffixes (ZZ, 2RS, …) change the closures, never these dimensions — a 6908-ZZ and 6908-2RS are the same size.
What the number means
- 6 — deep-groove ball bearing
- 9 — dimension series (thin section (6900))
- 08 — bore code × 5 = 40 mm
Neighboring sizes (thin section (6900) series)
| Designation | Bore | OD | Width |
|---|---|---|---|
| 6906 | 30 mm | 47 mm | 9 mm |
| 6907 | 35 mm | 55 mm | 10 mm |
| 6908 | 40 mm | 62 mm | 12 mm |
| 6909 | 45 mm | 68 mm | 12 mm |
| 6910 | 50 mm | 72 mm | 12 mm |
Same bore, other series
Fits the same 40 mm shaft with a different OD/width envelope and load capacity.
- 6808 — 40 × 52 × 7 mm (thin section (6800))
- 6008 — 40 × 68 × 15 mm (extra light (6000))
- 6208 — 40 × 80 × 18 mm (light (6200))
- 6308 — 40 × 90 × 23 mm (medium (6300))
Common suffixes on a 6908
| Suffix | Meaning |
|---|---|
| ZZ / 2Z | steel shields both sides (metal, non-contact) |
| Z | steel shield, one side |
| 2RS | contact rubber seals both sides (SKF 2RS1, NSK DDU, NTN LLU) |
| RS | contact rubber seal, one side |
| 2RZ | low-friction non-contact seals both sides (NSK VV, NTN LLB) |
| C3 | radial internal clearance greater than Normal (common in motors) |
| C2 | radial internal clearance smaller than Normal |
| NR | snap ring groove in the outer ring, with snap ring |
| P6 / P5 / P4 | ISO precision classes (≈ ABEC 3 / 5 / 7) |