1224-KM bearing: complete specifications & equivalents
The 1224-KM is a ISO 15 radial bearing sized 120 x 215 x 42 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 120 mm |
| Outer diameter D | 215 mm |
| Width B | 42 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 119 kN |
| Basic static load rating C0 | 53 kN |
| Fatigue load limit Pu | 2.12 kN |
| Reference speed (thermal) | 6300 rpm |
| Limiting speed (mechanical) | 4000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 6750 g |
| Manufacturer designation | 1224 KM |
| 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 | 4.724 in |
|---|---|
| Outer diameter D | 8.465 in |
| Width B | 1.654 in |
| ISO bore code | 24 |
| Radial section height (D−d)/2 | 47.5 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) | 30 of 32 |
| Bore above smallest 1200-series size | 114 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 1224-M | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 120×215×42 mm envelope with catalogue ratings within 10 %; 1224 M is the machined brass cage, open arrangement execution of this size — boundary dimensions interchangeable, only the seal/cage/bore execution differs. |
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 1224-KM model number is decoded
The 12xx series is the light/normal-section self-aligning ball bearing (ISO dimension series 02). the last two digits encode the bore: 1224 carries code 24 = 120 mm (code × 5). Envelope 120×215×42 mm (4.724×8.465×1.654 in) with a 47.5 mm radial section height, C 119 kN, C0 53 kN and Pu 2.12 kN. The open 1224 KM carries no shields or seals and relies on application lubrication and external sealing. The KM suffix identifies the machined brass cage execution. The K suffix marks a 1:12 tapered bore for direct mounting on a tapered shaft or with an adapter sleeve. Reference (thermal) speed 6300 r/min, limiting speed 4000 r/min, catalogue mass 6750 g.
Typical equipment & failure modes
Common applications
- mill and kiln auxiliary drives
- paper-machine rolls
- marine deck machinery
- crusher feeders
Known failure patterns
- lubricant starvation where no regreasing interval is maintained
- contamination wear when the open arrangement is used without adequate external sealing
- incorrect sleeve tightening that leaves the tapered bore loose or over-expanded, changing internal clearance
- adapter-sleeve fretting when the sleeve is not locked against the shaft shoulder
- cage damage from running beyond the limiting speed
- raceway smearing under marginal lubrication at start-up
Selection pitfalls — read before you substitute
- Assign interference to the rotating ring: on a 120 mm rotating shaft use a m6 seat with an H7 housing; reverse the logic if the outer ring rotates.
- At 120 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.
- On a sleeve-mounted 1224-KM, lock the sleeve against the shaft shoulder; a loose sleeve creeps and frets both the shaft and the bore.
- The KM suffix on 1224-KM denotes a machined brass cage: the choice for high speeds, marginal lubrication and shock/vibration duty, and temperature-tolerant where polymer cages are not.
- At 120 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.
- The spherical outer raceway lets 1224-KM tolerate shaft deflection, but it does not increase thrust capacity — combined loads still need an angular-contact or deep-groove bearing.
Frequently asked questions
What are the dimensions of 1224-KM?
SKF 1224 KM measures 120 mm bore × 215 mm OD × 42 mm width (4.724 × 8.465 × 1.654 in), mass about 6750 g. It is open, with no shields or seals.
How does the bore code in 1224 work?
The final two digits of 1224 are bore code 24, multiplied by 5 to give 120 mm.
Which fits should I use for 1224-KM?
With a rotating inner ring use roughly m6 on the shaft and H7 in the 215 mm housing; reverse the interference if the outer ring rotates.
How heavy is 1224-KM?
Catalogue mass is 6750 g for 1224 KM; 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.