NSK 6944ZZS dimensions and catalogue data
NSK 6944ZZS is a catalogue designation for a single-row deep groove ball bearing. Its published boundary dimensions are 220×300×38 mm (bore d × outside diameter D × width B).
The listed dynamic radial rating Cr is 161 kN and the static radial rating C0r is 169 kN.
What this marking establishes
Shielded ZZS catalogue type. Use the full marking for comparison; equal d×D×B dimensions do not establish interchangeability.
Using these figures safely
- The listed load ratings support bearing calculations; neither value is a universal permissible operating load. Actual life also depends on load direction, speed, lubrication, contamination and installation.
- Use the speed entry for the stated closure and lubrication condition. The open-bearing oil value must not be transferred to a double-sealed or double-shielded bearing.
- The shoulder diameters and fillet radius describe adjacent shaft or housing geometry, not alternative bearing boundary dimensions. Heavy axial loads and a rotating outer ring require an application-specific check.
- Clearance class, tolerance class, grease grade and vehicle or machine fitment are not established by this table row. A sealed or shielded catalogue designation is not a complete supply specification without its grease and other required suffixes.
- Optional N/NR groove and retaining-ring dimensions are not assigned to this record. Those options require their own complete designation and installation check.
- The approximate mass printed for the base row is not presented as the measured mass of this closed variant. A dash or omitted value means not established here, not zero.
- ZZS is explicitly listed as a shielded catalogue option. No speed is inferred from the adjacent ZZ/VV speed heading for this record.
Technical basis:NSK, Rolling Bearings for Industrial Machinery, E1103d (2025), Part C, C038–C039; checked 2026-10-01. Values are independently organized as a technical reference; this page is not an official drawing or a fitment approval.
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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 | Single row deep groove ball bearings | |
| Bore diameter | d | 220 mm |
| Outside diameter | D | 300 mm |
| Width | B | 38 mm |
| Basic dynamic load rating | C | 161 kN |
| Basic static load rating | C0 | 169 kN |
| Sealing | Shielded ZZS catalogue type |
Mounting dimensions4 parameters
| Parameter | Symbol | Value |
|---|---|---|
| Minimum shaft shoulder diameter | da min. | 231 mm |
| Maximum shaft shoulder diameter | da max. | 242 mm |
| Maximum housing shoulder diameter | Da max. | 289 mm |
| Maximum shaft or housing fillet radius | ra max. | 2 mm |
Boundary dimensions4 parameters
| Parameter | Symbol | Value |
|---|---|---|
| Bore diameter | d | 220 mm |
| Outside diameter | D | 300 mm |
| Bearing width | B | 38 mm |
| Minimum bearing chamfer | r min. | 2.1 mm |
Construction1 parameter
| Parameter | Symbol | Value |
|---|---|---|
| Catalogue closure construction | Shielded ZZS catalogue type |
Load ratings3 parameters
| Parameter | Symbol | Value |
|---|---|---|
| Basic dynamic radial load rating | Cr | 161000 N |
| Basic static radial load rating | C0r | 169000 N |
| Equivalent-load calculation factor | f0 | 16.6 |