61976-MA bearing: complete specifications & equivalents
The 61976-MA is a ISO 15 radial bearing sized 380 x 520 x 65 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 380 mm |
| Outer diameter D | 520 mm |
| Width B | 65 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 338 kN |
| Basic static load rating C0 | 540 kN |
| Fatigue load limit Pu | 10.8 kN |
| Reference speed (thermal) | 2400 rpm |
| Limiting speed (mechanical) | 1900 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 40000 g |
| Manufacturer designation | 61976 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 | 14.961 in |
|---|---|
| Outer diameter D | 20.472 in |
| Width B | 2.559 in |
| ISO bore code | 76 |
| Radial section height (D−d)/2 | 70 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) | 48 of 63 |
| Bore above smallest 61900-series size | 377 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61976 | NTN | full Dimensions and internal design equivalent — standard interchange. | NTN counterpart NTN 6976 on the same 380×520×65 mm envelope with ratings within 10 % — interchange after checking seal, cage and precision details on both pages. |
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 61976-MA model number is decoded
In the 61900-series, the last two digits encode the bore: 61976 carries code 76 = 380 mm (code × 5). The envelope is 380×520×65 mm (14.961×20.472×2.559 in) with a 70.0 mm radial section height, C 338 kN, C0 540 kN and Pu 10.8 kN. The open 61976 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 1900 r/min, catalogue mass 40000 g. A thin section saves space but leaves little margin for misalignment or shaft deflection.
Typical equipment & failure modes
Common applications
- large industrial gearboxes
- heavy conveyor drives
- hoists and winches
- industrial fans and blowers
Known failure patterns
- contamination wear when the open arrangement is used without external seals
- lubricant starvation where no regreasing interval is maintained
- raceway smearing under marginal lubrication at start-up
- electrical pitting in VFD-driven motors without shaft grounding
Selection pitfalls — read before you substitute
- Deep-groove geometry tolerates only minutes of misalignment; if the 520 mm housing bore cannot be aligned, move to a self-aligning bearing rather than shimming 61976-MA.
- Clearance suffixes follow the seal code in the designation stack (e.g. 61976-2Z/C3 in SKF spelling); no suffix means normal CN internal clearance.
- The MA suffix on 61976-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 40000 g quoted mass includes the heavier cage.
- Open 61976-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 61976-MA; run-to-failure on open deep-groove bearings is the dominant early-failure cause.
- Fillet radii must clear the 61976-MA chamfer so the 65 mm-wide ring seats square; an oversized shaft radius creates point contact on the ring face.
Frequently asked questions
What are the dimensions of 61976-MA?
The SKF 61976 MA measures 380 mm bore × 520 mm OD × 65 mm width (14.961 × 20.472 × 2.559 in), mass about 40000 g. It is open, with no shields or seals.
How does the bore code in 61976 work?
The final two digits of 61976 are bore code 76, multiplied by 5 to give 380 mm.
What is the difference between 61976-MA and a same-bore 62-series bearing?
Section height differs: 61976-MA has a 70 mm radial section and C 338 kN; always match d, D and B — same bore alone never makes two bearings interchangeable.
Which fits should I use for 61976-MA?
With a rotating inner ring use roughly m6 on the shaft and H7 in the 520 mm housing; reverse the interference if the outer ring rotates.
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.