4209-ATN9 bearing: complete specifications & equivalents
The 4209-ATN9 is a ISO 15 radial bearing sized 45 x 85 x 23 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 45 mm |
| Outer diameter D | 85 mm |
| Width B | 23 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 39 kN |
| Basic static load rating C0 | 36 kN |
| Fatigue load limit Pu | 1.53 kN |
| Reference speed (thermal) | 12000 rpm |
| Limiting speed (mechanical) | 6700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 540 g |
| Manufacturer designation | 4209 ATN9 |
| 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 & 4200-series range
| Bore d | 1.772 in |
|---|---|
| Outer diameter D | 3.346 in |
| Width B | 0.906 in |
| ISO bore code | 09 |
| Radial section height (D−d)/2 | 20 mm |
| Smallest bore in 4200-series | 10 mm |
| Largest outer diameter in 4200-series | 160 mm |
| Width range across 4200-series | 14–40 mm |
| Bore position in 4200-series (smallest first) | 10 of 19 |
| Bore above smallest 4200-series size | 35 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 62209-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 45×85×23 mm envelope as SKF 62209-2RS1, but catalogue C/C0 differ (39/36 kN vs 33.2/21.6 kN) — envelope match only after a load check. |
Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.
How the 4209-ATN9 model number is decoded
4209 ATN9 is a double-row deep-groove ball bearing in the 4200-series: the last two digits encode the bore: 4209 carries code 09 = 45 mm (code × 5). Two complete ball sets share the 45×85×23 mm (1.772×3.346×0.906 in) envelope, giving C 39 kN, C0 36 kN and Pu 1.53 kN, with reversing axial capacity a single-row bearing cannot match. ATN9 is the glass-fibre PA66 cage. Limiting speed 6700 r/min, mass 540 g. The arrangement is open and requires external sealing.
Typical equipment & failure modes
Common applications
- agricultural gearboxes
- belt take-up and tensioner units
- machine tool feed drives
- lifting and hoisting gear
Known failure patterns
- uneven load sharing between the two raceways when one ring is tilted
- polyamide cage embrittlement after sustained high-temperature service
- raceway smearing under marginal lubrication at start-up
- electrical pitting in VFD-driven motors without shaft grounding
Selection pitfalls — read before you substitute
- Two deep-groove raceways in 4209-ATN9 share the load but need parallel seats; tilting the 23 mm-wide assembly loads one row heavily and can spall it early.
- The wide 45×85×23 mm envelope is not interchangeable with a single-row 6209 — the housing and shaft shoulders differ, so design the seat for the double-row width from the start.
- Double-row 4209 is open and needs application sealing and lubrication; in dusty drives add external seals rather than expecting the bearing itself to stay clean.
- C 39 kN in a 23 mm width is the strength of the double-row design; use it for combined or reversing axial loads rather than pure radial duty where a slimmer single-row bearing would run cooler.
- The wide 45×85×23 mm envelope is not interchangeable with a single-row 6209 — the housing and shaft shoulders differ, so design the seat for the double-row width from the start.
- Do not preload 4209-ATN9 to silence it: a deep-groove ball bearing is not angular-contact, and axial preload only raises temperature and shortens grease life.
Frequently asked questions
What are the dimensions of 4209-ATN9?
Double-row 4209 ATN9 measures 45×85×23 mm (1.772×3.346×0.906 in), about 540 g.
What does ATN9 mean on 4209 ATN9?
A = double-row deep-groove arrangement, TN9 is a glass-fibre-reinforced polyamide 66 cage; it limits continuous temperature to roughly 100–120 °C.
Is 4209-ATN9 interchangeable with a 62-series single-row bearing?
No: although bore matches, OD and width differ and the seat shoulders must suit the wide double-row ring; 45×85×23 mm is its own envelope.
Does 4209-ATN9 run as fast as a single-row bearing?
Somewhat slower: SKF rates it to 6700 r/min; the two cages and wider grease volume generate more drag than a single-row 6209.
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.