6306 Bearing
Bore (d) 30 mm
Outside diameter (D) 72 mm
Width (B) 19 mm
Inches (bore × OD × width) 1.1811 × 2.8346 × 0.7480″
Deep-groove ball bearing, medium (6300) series. Seal/shield suffixes (ZZ, 2RS, …) change the closures, never these dimensions — a 6306-ZZ and 6306-2RS are the same size.
What the number means
- 6 — deep-groove ball bearing
- 3 — dimension series (medium (6300))
- 06 — bore code × 5 = 30 mm
Neighboring sizes (medium (6300) series)
| Designation | Bore | OD | Width |
|---|---|---|---|
| 6304 | 20 mm | 52 mm | 15 mm |
| 6305 | 25 mm | 62 mm | 17 mm |
| 6306 | 30 mm | 72 mm | 19 mm |
| 6307 | 35 mm | 80 mm | 21 mm |
| 6308 | 40 mm | 90 mm | 23 mm |
Same bore, other series
Fits the same 30 mm shaft with a different OD/width envelope and load capacity.
- 6806 — 30 × 42 × 7 mm (thin section (6800))
- 6906 — 30 × 47 × 9 mm (thin section (6900))
- 6006 — 30 × 55 × 13 mm (extra light (6000))
- 6206 — 30 × 62 × 16 mm (light (6200))
Common suffixes on a 6306
| 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) |