61856-MA bearing: complete specifications & equivalents
The 61856-MA is a ISO 15 radial bearing sized 280 x 350 x 33 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 280 mm |
| Outer diameter D | 350 mm |
| Width B | 33 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 138 kN |
| Basic static load rating C0 | 200 kN |
| Fatigue load limit Pu | 4.75 kN |
| Reference speed (thermal) | 3400 rpm |
| Limiting speed (mechanical) | 2800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 7250 g |
| Manufacturer designation | 61856 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 & 61800-series range
| Bore d | 11.024 in |
|---|---|
| Outer diameter D | 13.78 in |
| Width B | 1.299 in |
| ISO bore code | 56 |
| Radial section height (D−d)/2 | 35 mm |
| Smallest bore in 61800-series | 1 mm |
| Largest outer diameter in 61800-series | 1820 mm |
| Width range across 61800-series | 1–140 mm |
| Bore position in 61800-series (smallest first) | 46 of 74 |
| Bore above smallest 61800-series size | 279 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61856 | SKF | full Dimensions and internal design equivalent — standard interchange. | SKF SKF 61856 (open arrangement) shares the 280×350×33 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 61856-MA model number is decoded
In the 61800-series, the last two digits encode the bore: 61856 carries code 56 = 280 mm (code × 5). The envelope is 280×350×33 mm (11.024×13.78×1.299 in) with a 35.0 mm radial section height, C 138 kN, C0 200 kN and Pu 4.75 kN. The open 61856 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 2800 r/min, catalogue mass 7250 g. A thin section saves space but leaves little margin for misalignment or shaft deflection.
Typical equipment & failure modes
Common applications
- lay shafts and idler shafts
- textile and packaging machinery
- slew and indexing drives
- large industrial gearboxes
Known failure patterns
- contamination wear when the open arrangement is used without external seals
- lubricant starvation where no regreasing interval is maintained
- electrical pitting in VFD-driven motors without shaft grounding
- edge loading from shaft deflection or housing misalignment
Selection pitfalls — read before you substitute
- The fatigue load limit is 4.75 kN; it feeds the equivalent-mean-load check, not the basic life calculation — do not substitute one for the other.
- The fatigue load limit is 4.75 kN; it feeds the equivalent-mean-load check, not the basic life calculation — do not substitute one for the other.
- The MA suffix on 61856-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 7250 g quoted mass includes the heavier cage.
- Open 61856-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 61856-MA; run-to-failure on open deep-groove bearings is the dominant early-failure cause.
- Assign interference to the rotating ring: on a conventional shaft-mounted 280 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.
Frequently asked questions
What are the dimensions of 61856-MA?
The SKF 61856 MA measures 280 mm bore × 350 mm OD × 33 mm width (11.024 × 13.78 × 1.299 in), mass about 7250 g. It is open, with no shields or seals.
How does the bore code in 61856 work?
The final two digits of 61856 are bore code 56, multiplied by 5 to give 280 mm.
What is the speed rating of 61856-MA?
SKF lists a 3400 r/min thermal reference speed and a 2800 r/min mechanical limiting speed for 61856 MA; real limits also depend on lubrication and fits.
What is the difference between 61856-MA and a same-bore 62-series bearing?
Section height differs: 61856-MA has a 35 mm radial section and C 138 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.