108-TN9 bearing: complete specifications & equivalents
The 108-TN9 is a ISO 15 radial bearing sized 8 x 22 x 7 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 8 mm |
| Outer diameter D | 22 mm |
| Width B | 7 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 2.65 kN |
| Basic static load rating C0 | 0.56 kN |
| Fatigue load limit Pu | 0.029 kN |
| Reference speed (thermal) | 60000 rpm |
| Limiting speed (mechanical) | 40000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 14 g |
| Manufacturer designation | 108 TN9 |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018) |
| Last verified | 2026-09-27 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018)) · extracted 2026-09-27
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018)); SKF® and SKF Explorer® are trademarks of AB SKF, used here for identification only — mpnbase is not an authorized SKF distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at skf.com.
Dimensions in inches & 1200-series range
| Bore d | 0.315 in |
|---|---|
| Outer diameter D | 0.866 in |
| Width B | 0.276 in |
| ISO bore code | 08 |
| Radial section height (D−d)/2 | 7 mm |
| Smallest bore in 1200-series | 6 mm |
| Largest outer diameter in 1200-series | 230 mm |
| Width range across 1200-series | 6–154 mm |
| Bore position in 1200-series (smallest first) | 3 of 32 |
| Bore above smallest 1200-series size | 2 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the 108-TN9 model number is decoded
The 10xx series is a self-aligning ball bearing family. the final digit of 108 is the bore in millimetres: 108 TN9 fits a 8 mm shaft (direct miniature spelling). Envelope 8×22×7 mm (0.315×0.866×0.276 in) with a 7.0 mm radial section height, C 2.65 kN, C0 0.56 kN and Pu 0.029 kN. The open 108 TN9 carries no shields or seals and relies on application lubrication and external sealing. The TN9 suffix identifies the glass-fibre-reinforced polyamide 66 cage execution. The bore is cylindrical (straight), for a press-fit on a 8 mm shaft. Reference (thermal) speed 60000 r/min, limiting speed 40000 r/min, catalogue mass 14 g.
Typical equipment & failure modes
Common applications
- woodworking machine spindles
- light gearbox layshafts
- food-processing conveyors
- small electric motors
Known failure patterns
- contamination wear when the open arrangement is used without adequate external sealing
- lubricant starvation where no regreasing interval is maintained
- raceway smearing under marginal lubrication at start-up
- electrical pitting in VFD-driven motors without shaft grounding
Selection pitfalls — read before you substitute
- Catalogue ratings for 108-TN9 (C 2.65 kN, C0 0.56 kN) are SKF figures from PUB BU/P1 17000; geometry revisions can change ratings without changing the designation, so keep the catalogue edition with the specification.
- Self-aligning ball bearings tolerate up to roughly 2–3° of static misalignment, but the sealed 108-TN9 (2RS1) allows less — the lip seal binds before the spherical raceway does.
- The TN9 suffix on 108-TN9 denotes a glass-fibre-reinforced polyamide 66 cage: quiet and light at the 40000 r/min limiting speed, but it softens above roughly 120 °C — check the oil temperature in hot drives.
- Fillet radii must clear the 108-TN9 chamfer so the 7 mm-wide ring seats square; an oversized shaft radius creates point contact on the ring face.
- Self-aligning ball bearings tolerate up to roughly 2–3° of static misalignment, but the sealed 108-TN9 (2RS1) allows less — the lip seal binds before the spherical raceway does.
- Assign interference to the rotating ring: on a 8 mm rotating shaft use a j5/k5 seat with an H7 housing; reverse the logic if the outer ring rotates.
Frequently asked questions
What are the dimensions of 108-TN9?
SKF 108 TN9 measures 8 mm bore × 22 mm OD × 7 mm width (0.315 × 0.866 × 0.276 in), mass about 14 g. It is open, with no shields or seals.
How do I read the 108 designation?
Miniature self-aligning bearings print the bore as the final digit, so 108 is a 8 mm bearing; the leading digits give the section family.
What is the speed rating of 108-TN9?
SKF lists a 60000 r/min thermal reference speed and a 40000 r/min mechanical limiting speed for 108 TN9; real limits also depend on lubrication and fits.
How much misalignment can 108-TN9 tolerate?
Self-aligning ball bearings tolerate roughly 2–3° of static misalignment for open executions; sealed 2RS1 variants like 108-TN9 allow less (about 1°) because the seal lip binds first.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018) on 2026-09-27. Read our editorial & correction policy.