61924-MA (brass cage) bearing: complete specifications & equivalents
The 61924-MA is a ISO 15 radial bearing sized 120 x 165 x 22 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 | 165 mm |
| Width B | 22 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 55.3 kN |
| Basic static load rating C0 | 57 kN |
| Fatigue load limit Pu | 2.04 kN |
| Reference speed (thermal) | 8000 rpm |
| Limiting speed (mechanical) | 6700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1400 g |
| Manufacturer designation | 61924 MA |
| 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 & 61900-series range
| Bore d | 4.724 in |
|---|---|
| Outer diameter D | 6.496 in |
| Width B | 0.866 in |
| ISO bore code | 24 |
| Radial section height (D−d)/2 | 22.5 mm |
| Smallest bore in 61900-series | 3 mm |
| Largest outer diameter in 61900-series | 1120 mm |
| Width range across 61900-series | 3–118 mm |
| Bore position in 61900-series (smallest first) | 31 of 63 |
| Bore above smallest 61900-series size | 117 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61924-ZZ | NSK | full Dimensions and internal design equivalent — standard interchange. | NSK counterpart NSK 6924ZZ on the same 120×165×22 mm envelope with ratings within 10 % — interchange after checking seal, cage and precision details on both pages. |
| 61924-NSK | NSK | full Dimensions and internal design equivalent — standard interchange. | NSK counterpart NSK 6924 on the same 120×165×22 mm envelope with ratings within 10 % — interchange after checking seal, cage and precision details on both pages. |
| 61924-NTN | NTN | full Dimensions and internal design equivalent — standard interchange. | NTN counterpart 6924 on the same 120×165×22 mm envelope with ratings within 10 % — interchange after checking seal, cage and precision details on both pages. |
| 61924-2RS | NTN | full Dimensions and internal design equivalent — standard interchange. | NTN counterpart 6924LLU on the same 120×165×22 mm envelope with ratings within 10 % — interchange after checking seal, cage and precision details on both pages. |
| 61924-ZZ-NTN | NTN | full Dimensions and internal design equivalent — standard interchange. | NTN counterpart 6924ZZ on the same 120×165×22 mm envelope with ratings within 10 % — interchange after checking seal, cage and precision details on both pages. |
| 61924 | SKF | full Dimensions and internal design equivalent — standard interchange. | SKF SKF 61924 (open arrangement) shares the 120×165×22 mm envelope with ratings within 10 % — execution variant of the same size; boundary dimensions interchangeable. |
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 61924-MA model number is decoded
In the 61900-series, the last two digits encode the bore: 61924 carries code 24 = 120 mm (code × 5). The envelope is 120×165×22 mm (4.724×6.496×0.866 in) with a 22.5 mm radial section height, C 55.3 kN, C0 57 kN and Pu 2.04 kN. The open 61924 MA carries no shields or seals and relies on application lubrication and external sealing. The MA suffix identifies the machined brass cage execution, a separate order number from the pressed-steel version. Limiting speed 6700 r/min, catalogue mass 1400 g. A thin section saves space but leaves little margin for misalignment or shaft deflection.
Typical equipment & failure modes
Common applications
- compressor drives
- machine tool auxiliaries
- agricultural gearboxes
- space-constrained gearboxes
Known failure patterns
- contamination wear when the open arrangement is used without external seals
- lubricant starvation where no regreasing interval is maintained
- 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 conventional shaft-mounted 120 mm position the inner ring rotates, so use a k5/m6 shaft seat with an H7 housing — reverse the logic if the outer ring rotates.
- Catalogue ratings for 61924-MA (C 55.3 kN, C0 57 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.
- The MA suffix on 61924-MA denotes a machined brass cage: it is the choice for high speeds, marginal lubrication and shock/vibration duty, and it is temperature-tolerant where polymer cages are not — the 1400 g quoted mass includes the heavier cage.
- Open 61924-MA needs external sealing at the arrangement level; in dusty housings its life depends entirely on those external seals and the regreasing schedule.
- Plan a relubrication interval for 61924-MA; run-to-failure on open deep-groove bearings is the dominant early-failure cause.
- Fillet radii must clear the 61924-MA chamfer so the 22 mm-wide ring seats square; an oversized shaft radius creates point contact on the ring face.
- For positions that need relubrication, choose the open execution of 61924 and design the housing with a grease path; shielded and sealed versions are intended as fit-and-forget units.
- Sealed SKF units are filled with a lithium-based grease for general service; food-grade, low-temperature and high-temperature fills are order options and are not field-interchangeable once the unit is sealed.
Frequently asked questions
What are the dimensions of 61924-MA?
The SKF 61924 MA measures 120 mm bore × 165 mm OD × 22 mm width (4.724 × 6.496 × 0.866 in), mass about 1400 g. It is open, with no shields or seals.
How does the bore code in 61924 work?
The final two digits of 61924 are bore code 24, multiplied by 5 to give 120 mm.
What load can 61924-MA take?
Catalogue values for 61924 MA: dynamic C 55.3 kN, static C0 57 kN, fatigue limit Pu 2.04 kN. Use C in life calculation and C0 for static checks at 120 mm bore.
What is the speed rating of 61924-MA?
SKF lists a 8000 r/min thermal reference speed and a 6700 r/min mechanical limiting speed for 61924 MA; real limits also depend on lubrication and fits.
What is the difference between 61924-MA and a same-bore 62-series bearing?
Section height differs: 61924-MA has a 22.5 mm radial section and C 55.3 kN; always match d, D and B — same bore alone never makes two bearings interchangeable.
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.