61964-MA bearing: complete specifications & equivalents
The 61964-MA is a ISO 15 radial bearing sized 320 x 440 x 56 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 320 mm |
| Outer diameter D | 440 mm |
| Width B | 56 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 276 kN |
| Basic static load rating C0 | 400 kN |
| Fatigue load limit Pu | 8.65 kN |
| Reference speed (thermal) | 2800 rpm |
| Limiting speed (mechanical) | 2400 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 25500 g |
| Manufacturer designation | 61964 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 | 12.598 in |
|---|---|
| Outer diameter D | 17.323 in |
| Width B | 2.205 in |
| ISO bore code | 64 |
| Radial section height (D−d)/2 | 60 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) | 45 of 63 |
| Bore above smallest 61900-series size | 317 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61964 | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | NTN bearing NTN 6964 on the same 320×440×56 mm envelope, but catalogue C/C0 differ (276/400 kN vs 315/405 kN) — envelope interchange 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 61964-MA model number is decoded
In the 61900-series, the last two digits encode the bore: 61964 carries code 64 = 320 mm (code × 5). The envelope is 320×440×56 mm (12.598×17.323×2.205 in) with a 60.0 mm radial section height, C 276 kN, C0 400 kN and Pu 8.65 kN. The open 61964 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 2400 r/min, catalogue mass 25500 g. A thin section saves space but leaves little margin for misalignment or shaft deflection.
Typical equipment & failure modes
Common applications
- industrial fans and blowers
- mill and kiln auxiliaries
- pulp and paper machinery
- marine deck machinery
Known failure patterns
- contamination wear when the open arrangement is used without external seals
- lubricant starvation where no regreasing interval is maintained
- rolling-contact fatigue spalling once the catalogue L10 life is exceeded
- brinelling from static overload or hammer blows during mounting
Selection pitfalls — read before you substitute
- Do not preload 61964-MA to silence it: a deep-groove ball bearing is not angular-contact, and axial preload only raises temperature and shortens grease life.
- Catalogue ratings for 61964-MA (C 276 kN, C0 400 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 61964-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 25500 g quoted mass includes the heavier cage.
- Open 61964-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 61964-MA; run-to-failure on open deep-groove bearings is the dominant early-failure cause.
- Fillet radii must clear the 61964-MA chamfer so the 56 mm-wide ring seats square; an oversized shaft radius creates point contact on the ring face.
Frequently asked questions
What are the dimensions of 61964-MA?
The SKF 61964 MA measures 320 mm bore × 440 mm OD × 56 mm width (12.598 × 17.323 × 2.205 in), mass about 25500 g. It is open, with no shields or seals.
How does the bore code in 61964 work?
The final two digits of 61964 are bore code 64, multiplied by 5 to give 320 mm.
How heavy is 61964-MA?
Catalogue mass is 25500 g for 61964 MA; seal and cage executions of the same envelope differ by a few grams.
What load can 61964-MA take?
Catalogue values for 61964 MA: dynamic C 276 kN, static C0 400 kN, fatigue limit Pu 8.65 kN. Use C in life calculation and C0 for static checks at 320 mm bore.
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.