4303-ATN9 bearing: complete specifications & equivalents
The 4303-ATN9 is a ISO 15 radial bearing sized 17 x 47 x 19 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 17 mm |
| Outer diameter D | 47 mm |
| Width B | 19 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 19.5 kN |
| Basic static load rating C0 | 13.2 kN |
| Fatigue load limit Pu | 0.56 kN |
| Reference speed (thermal) | 24000 rpm |
| Limiting speed (mechanical) | 13000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 160 g |
| Manufacturer designation | 4303 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 & 4300-series range
| Bore d | 0.669 in |
|---|---|
| Outer diameter D | 1.85 in |
| Width B | 0.748 in |
| ISO bore code | 03 |
| Radial section height (D−d)/2 | 15 mm |
| Smallest bore in 4300-series | 12 mm |
| Largest outer diameter in 4300-series | 160 mm |
| Width range across 4300-series | 17–55 mm |
| Bore position in 4300-series (smallest first) | 3 of 14 |
| Bore above smallest 4300-series size | 5 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 62303-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×47×19 mm envelope as SKF 62303-2RS1, but catalogue C/C0 differ (19.5/13.2 kN vs 13.5/6.55 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 4303-ATN9 model number is decoded
4303 ATN9 is a double-row deep-groove ball bearing in the 4300-series: bore code 03 follows the 10/12/15/17 mm exception table, so 4303 fits a 17 mm shaft. Two complete ball sets share the 17×47×19 mm (0.669×1.85×0.748 in) envelope, giving C 19.5 kN, C0 13.2 kN and Pu 0.56 kN, with reversing axial capacity a single-row bearing cannot match. ATN9 is the glass-fibre PA66 cage. Limiting speed 13000 r/min, mass 160 g. The arrangement is open and requires external sealing.
Typical equipment & failure modes
Common applications
- gearbox layshafts with reversing axial load
- agricultural gearboxes
- belt take-up and tensioner units
- machine tool feed drives
Known failure patterns
- uneven load sharing between the two raceways when one ring is tilted
- polyamide cage embrittlement after sustained high-temperature service
- electrical pitting in VFD-driven motors without shaft grounding
- edge loading from shaft deflection or housing misalignment
Selection pitfalls — read before you substitute
- The ATN9 cage is glass-fibre-reinforced polyamide 66: it is light and quiet but caps continuous service around 100–120 °C in oil/grease — above that use the pressed-steel or machined-cage version of the 17 mm position.
- Two deep-groove raceways in 4303-ATN9 share the load but need parallel seats; tilting the 19 mm-wide assembly loads one row heavily and can spall it early.
- The wide 17×47×19 mm envelope is not interchangeable with a single-row 6203 — the housing and shaft shoulders differ, so design the seat for the double-row width from the start.
- Double-row 4303 is open and needs application sealing and lubrication; in dusty drives add external seals rather than expecting the bearing itself to stay clean.
- Fit both rings square on the shoulders: the narrow internal land between the two raceways of 4303-ATN9 is sensitive to cocking during pressing.
- Catalogue ratings for 4303-ATN9 (C 19.5 kN, C0 13.2 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 4303-ATN9?
Double-row 4303 ATN9 measures 17×47×19 mm (0.669×1.85×0.748 in), about 160 g.
What does ATN9 mean on 4303 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.
How is 4303-ATN9 lubricated and sealed?
The ATN9 execution is open and greased/oiled by the application; provide external lip seals and a regreasing path for dirty duty.
What load does 4303-ATN9 carry?
C 19.5 kN, C0 13.2 kN and Pu 0.56 kN per catalogue 17000; both rows share the load when the rings sit parallel.
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.