1224-M bearing: complete specifications & equivalents
The 1224-M 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 M |
| 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-KM | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 120×215×42 mm envelope with catalogue ratings within 10 %; 1224 KM is the machined brass cage, open arrangement, tapered bore 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-M 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 M carries no shields or seals and relies on application lubrication and external sealing. The M suffix identifies the machined brass cage execution. The bore is cylindrical (straight), for a press-fit on a 120 mm shaft. Reference (thermal) speed 6300 r/min, limiting speed 4000 r/min, catalogue mass 6750 g.
Typical equipment & failure modes
Common applications
- crusher feeders
- large industrial gearboxes
- material-handling winches
- large conveyor drives
Known failure patterns
- contamination wear when the open arrangement is used without adequate external sealing
- lubricant starvation where no regreasing interval is maintained
- excessive misalignment loading one ball row heavily and spalling it early
- rolling-contact fatigue spalling once the catalogue L10 life is exceeded
Selection pitfalls — read before you substitute
- The fatigue load limit is 2.12 kN; it feeds the equivalent-mean-load check, not the basic life calculation — do not substitute one for the other.
- Self-aligning ball bearings tolerate up to roughly 2–3° of static misalignment, but the sealed 1224-M (2RS1) allows less — the lip seal binds before the spherical raceway does.
- The M suffix on 1224-M denotes a machined brass cage: the choice for high speeds, marginal lubrication and shock/vibration duty, and temperature-tolerant where polymer cages are not.
- Fillet radii must clear the 1224-M chamfer so the 42 mm-wide ring seats square; an oversized shaft radius creates point contact on the ring face.
- Self-aligning ball bearings tolerate up to roughly 2–3° of static misalignment, but the sealed 1224-M (2RS1) allows less — the lip seal binds before the spherical raceway does.
- 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.
Frequently asked questions
What are the dimensions of 1224-M?
SKF 1224 M 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.
What is the speed rating of 1224-M?
SKF lists a 6300 r/min thermal reference speed and a 4000 r/min mechanical limiting speed for 1224 M; real limits also depend on lubrication and fits.
How much misalignment can 1224-M tolerate?
Self-aligning ball bearings tolerate roughly 2–3° of static misalignment for open executions; sealed 2RS1 variants like 1224-M allow less (about 1°) because the seal lip binds first.
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.