4218-ATN9 bearing: complete specifications & equivalents
The 4218-ATN9 is a ISO 15 radial bearing sized 90 x 160 x 40 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 90 mm |
| Outer diameter D | 160 mm |
| Width B | 40 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 112 kN |
| Basic static load rating C0 | 122 kN |
| Fatigue load limit Pu | 4.65 kN |
| Reference speed (thermal) | 6300 rpm |
| Limiting speed (mechanical) | 3400 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 3200 g |
| Manufacturer designation | 4218 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 | 3.543 in |
|---|---|
| Outer diameter D | 6.299 in |
| Width B | 1.575 in |
| ISO bore code | 18 |
| Radial section height (D−d)/2 | 35 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) | 19 of 19 |
| Bore above smallest 4200-series size | 80 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the 4218-ATN9 model number is decoded
4218 ATN9 is a double-row deep-groove ball bearing in the 4200-series: the last two digits encode the bore: 4218 carries code 18 = 90 mm (code × 5). Two complete ball sets share the 90×160×40 mm (3.543×6.299×1.575 in) envelope, giving C 112 kN, C0 122 kN and Pu 4.65 kN, with reversing axial capacity a single-row bearing cannot match. ATN9 is the glass-fibre PA66 cage. Limiting speed 3400 r/min, mass 3200 g. The arrangement is open and requires external sealing.
Typical equipment & failure modes
Common applications
- double-supported pump impeller shafts
- gearbox layshafts with reversing axial load
- agricultural gearboxes
- belt take-up and tensioner units
Known failure patterns
- uneven load sharing between the two raceways when one ring is tilted
- polyamide cage embrittlement after sustained high-temperature service
- edge loading from shaft deflection or housing misalignment
- rolling-contact fatigue spalling once the catalogue L10 life is exceeded
Selection pitfalls — read before you substitute
- Fit both rings square on the shoulders: the narrow internal land between the two raceways of 4218-ATN9 is sensitive to cocking during pressing.
- 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 90 mm position.
- Two deep-groove raceways in 4218-ATN9 share the load but need parallel seats; tilting the 40 mm-wide assembly loads one row heavily and can spall it early.
- The wide 90×160×40 mm envelope is not interchangeable with a single-row 6218 — the housing and shaft shoulders differ, so design the seat for the double-row width from the start.
- The wide 90×160×40 mm envelope is not interchangeable with a single-row 6218 — the housing and shaft shoulders differ, so design the seat for the double-row width from the start.
- At 90 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.
Frequently asked questions
What are the dimensions of 4218-ATN9?
Double-row 4218 ATN9 measures 90×160×40 mm (3.543×6.299×1.575 in), about 3200 g.
What does ATN9 mean on 4218 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.
Does 4218-ATN9 run as fast as a single-row bearing?
Somewhat slower: SKF rates it to 3400 r/min; the two cages and wider grease volume generate more drag than a single-row 6218.
How is 4218-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.
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.