624 Bearing
Bore (d) 4 mm
Outside diameter (D) 13 mm
Width (B) 5 mm
Inches (bore × OD × width) 0.1575 × 0.5118 × 0.1969″
Deep-groove ball bearing, miniature (62x) series. Seal/shield suffixes (ZZ, 2RS, …) change the closures, never these dimensions — a 624-ZZ and 624-2RS are the same size.
What the number means
- 6 — deep-groove ball bearing
- 2 — miniature (62x) series
- 4 — bore in mm (4 mm)
Neighboring sizes (miniature (62x) series)
| Designation | Bore | OD | Width |
|---|---|---|---|
| 623 | 3 mm | 10 mm | 4 mm |
| 624 | 4 mm | 13 mm | 5 mm |
| 625 | 5 mm | 16 mm | 5 mm |
| 626 | 6 mm | 19 mm | 6 mm |
Same bore, other series
Fits the same 4 mm shaft with a different OD/width envelope and load capacity.
- 604 — 4 × 12 × 4 mm (miniature (60x))
Common suffixes on a 624
| 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) |