NACHI 6808NKE dimensions and model data
NACHI 6808NKE is a catalogue-listed deep groove ball bearing measuring 40×52×7 mm (bore d × outside diameter D × width B), with one non-contact seal.
Reading this exact marking
In the base number 6808, 6 identifies the deep groove ball bearing type and 8 is the diameter-series digit. The bore code 08 corresponds to the 40 mm bore in this model row; it is not itself a diameter in millimetres.
The base designation is 6808. The listed suffix NKE specifies one non-contact seal. NSE/NSE9 denotes a contact seal; NKE/NKE9 denotes a non-contact seal. ZE and ZZE distinguish one and two shields. Do not silently remove the 9 or the leading 2 when matching a model.
Lubrication-qualified speed
This table names the newer NSE9/NKE9 seals in its speed headings. It does not separately establish a speed for this earlier NSE/NKE suffix, so none is assigned here. The oil-speed column is limited to open and ZE versions; it is not assigned to this configuration.
Load calculation reference
This row supplies f0 = 16.2. For positive radial load Fr, select the catalogue factors using f0×Fa/C0r, with Fa and C0r expressed in the same force unit. If Fa/Fr ≤ e, Pr = Fr. Above e, Pr = 0.56Fr + YFa. For the static check use P0r = max(Fr, 0.6Fr + 0.5Fa).
Catalogue factors and limits
| f0×Fa/C0r | e | Y above e |
|---|---|---|
| 0.172 | 0.19 | 2.30 |
| 0.345 | 0.22 | 1.99 |
| 0.689 | 0.26 | 1.71 |
| 1.03 | 0.28 | 1.55 |
| 1.38 | 0.30 | 1.45 |
| 2.07 | 0.34 | 1.31 |
| 3.45 | 0.38 | 1.15 |
| 5.17 | 0.42 | 1.04 |
| 6.89 | 0.44 | 1.00 |
The table gives discrete reference points, not a universal Y value. No interpolation or extrapolation rule is asserted here; verify intermediate conditions against the applicable engineering method. The Fa/Fr branch test is undefined when Fr is zero.
Versions listed alongside 6808
- 6808— Open
- 6808ZE— One shield
- 6808ZZE— Two shields
- 6808NSE— One contact seal
- 6808-2NSE— Two contact seals
- 6808NKE— One non-contact seal
- 6808-2NKE— Two non-contact seals
Selection limits and missing data
- The catalogue row gives Cr = 6.2 kN and C0r = 4.15 kN. These are load-rating inputs for calculations, not a statement of maximum permissible service load.
- The adjacent shaft shoulder must meet da ≥ 42 mm, the housing shoulder Da ≤ 50 mm, and the adjacent fillet ra ≤ 0.3 mm for the illustrated mounting geometry.
- The 0.033 kg mass is reported once for the shared catalogue row; separate masses for each closure version are not published in this table.
- A catalogue speed limit does not approve the actual operating speed: load, lubrication, fits, temperature and surrounding hardware still need checking.
- The listed marking does not establish a particular internal clearance, ABEC grade, temperature range or grease life. Extra ordering suffixes must be checked separately.
- Matching boundary dimensions is only a starting point for comparison, not proof of interchangeability or equipment fitment.
Technical basis:NACHI Deep Groove Ball Bearings, catalogue B3402E-2, imprint 2026.7; physical PDF pages 3–5. Source checked 2026-10-02. Facts are independently organised for query and comparison; the original PDF and illustrations are not redistributed.
Product specifications
Metric and imperial values are paired where the manufacturer provides both. Expand a section to review its parameters.
Core specifications7 parameters
| Parameter | Symbol | Value |
|---|---|---|
| Variant / construction | Deep groove ball bearing | |
| Bore diameter | d | 40 mm |
| Outside diameter | D | 52 mm |
| Width | B | 7 mm |
| Basic dynamic load rating | C | 6.2 kN |
| Basic static load rating | C0 | 4.15 kN |
| Sealing | One non-contact seal |
Mounting dimensions3 parameters
| Parameter | Symbol | Value |
|---|---|---|
| Minimum shaft shoulder diameter | da min. | 42 mm |
| Maximum housing shoulder diameter | Da max. | 50 mm |
| Maximum adjacent fillet radius | ra max. | 0.3 mm |
Boundary dimensions4 parameters
| Parameter | Symbol | Value |
|---|---|---|
| Bore diameter | d | 40 mm |
| Outside diameter | D | 52 mm |
| Bearing width | B | 7 mm |
| Minimum bearing chamfer | r min. | 0.3 mm |
Construction2 parameters
| Parameter | Symbol | Value |
|---|---|---|
| Closure arrangement | One non-contact seal | |
| Listed closure suffix | NKE |
Equivalent-load factors1 parameter
| Parameter | Symbol | Value |
|---|---|---|
| Catalogue load calculation factor | f0 | 16.2 |
Load ratings2 parameters
| Parameter | Symbol | Value |
|---|---|---|
| Basic dynamic radial load rating | Cr | 6200 N |
| Basic static radial load rating | C0r | 4150 N |
Reference mass1 parameter
| Parameter | Symbol | Value |
|---|---|---|
| Catalogue row mass (variants not individually specified) | 0.033 kg |