127-TN9 bearing: complete specifications & equivalents
The 127-TN9 is a ISO 15 radial bearing sized 7 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 | 7 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) | 63000 rpm |
| Limiting speed (mechanical) | 40000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 14 g |
| Manufacturer designation | 127 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 | 0.276 in |
|---|---|
| Outer diameter D | 0.866 in |
| Width B | 0.276 in |
| ISO bore code | 27 |
| Radial section height (D−d)/2 | 7.5 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) | 2 of 32 |
| Bore above smallest 1200-series size | 1 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the 127-TN9 model number is decoded
The 12xx series is the light/normal-section self-aligning ball bearing (ISO dimension series 02). the final digit of 127 is the bore in millimetres: 127 TN9 fits a 7 mm shaft (direct miniature spelling). Envelope 7×22×7 mm (0.276×0.866×0.276 in) with a 7.5 mm radial section height, C 2.65 kN, C0 0.56 kN and Pu 0.029 kN. The open 127 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 7 mm shaft. Reference (thermal) speed 63000 r/min, limiting speed 40000 r/min, catalogue mass 14 g.
Typical equipment & failure modes
Common applications
- light gearbox layshafts
- food-processing conveyors
- small electric motors
- conveyor idler rollers
Known failure patterns
- lubricant starvation where no regreasing interval is maintained
- contamination wear when the open arrangement is used without adequate external sealing
- rolling-contact fatigue spalling once the catalogue L10 life is exceeded
- brinelling from static overload or hammer blows during mounting
Selection pitfalls — read before you substitute
- At 7 mm bore, C3 clearance is the safe choice when interference fits plus temperature rise consume the CN clearance; a hot tight bearing with no residual clearance fails fast.
- Assign interference to the rotating ring: on a 7 mm rotating shaft use a j5/k5 seat with an H7 housing; reverse the logic if the outer ring rotates.
- The TN9 suffix on 127-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.
- Self-aligning ball bearings tolerate up to roughly 2–3° of static misalignment, but the sealed 127-TN9 (2RS1) allows less — the lip seal binds before the spherical raceway does.
- Assign interference to the rotating ring: on a 7 mm rotating shaft use a j5/k5 seat with an H7 housing; reverse the logic if the outer ring rotates.
- Catalogue ratings for 127-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.
Frequently asked questions
What are the dimensions of 127-TN9?
SKF 127 TN9 measures 7 mm bore × 22 mm OD × 7 mm width (0.276 × 0.866 × 0.276 in), mass about 14 g. It is open, with no shields or seals.
How do I read the 127 designation?
Miniature self-aligning bearings print the bore as the final digit, so 127 is a 7 mm bearing; the leading digits give the section family.
Which fits should I use for 127-TN9?
With a rotating inner ring use roughly j5/k5 on the shaft and H7 in the 22 mm housing; reverse the interference if the outer ring rotates.
How heavy is 127-TN9?
Catalogue mass is 14 g for 127 TN9; seal and cage executions of the same envelope differ by a few grams.
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.