61888-MA bearing: complete specifications & equivalents
The 61888-MA is a ISO 15 radial bearing sized 440 x 540 x 46 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 440 mm |
| Outer diameter D | 540 mm |
| Width B | 46 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 255 kN |
| Basic static load rating C0 | 440 kN |
| Fatigue load limit Pu | 8.5 kN |
| Reference speed (thermal) | 2200 rpm |
| Limiting speed (mechanical) | 1800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 22500 g |
| Manufacturer designation | 61888 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 | 17.323 in |
|---|---|
| Outer diameter D | 21.26 in |
| Width B | 1.811 in |
| ISO bore code | 88 |
| Radial section height (D−d)/2 | 50 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) | 54 of 74 |
| Bore above smallest 61800-series size | 439 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61888 | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | NTN bearing NTN 6888 on the same 440×540×46 mm envelope, but catalogue C/C0 differ (255/440 kN vs 292/420 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 61888-MA model number is decoded
In the 61800-series, the last two digits encode the bore: 61888 carries code 88 = 440 mm (code × 5). The envelope is 440×540×46 mm (17.323×21.26×1.811 in) with a 50.0 mm radial section height, C 255 kN, C0 440 kN and Pu 8.5 kN. The open 61888 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 1800 r/min, catalogue mass 22500 g. A thin section saves space but leaves little margin for misalignment or shaft deflection.
Typical equipment & failure modes
Common applications
- marine deck machinery
- crusher auxiliary drives
- space-constrained gearboxes
- clutch and transmission assemblies
Known failure patterns
- contamination wear when the open arrangement is used without external seals
- lubricant starvation where no regreasing interval is maintained
- fretting corrosion on a creeping shaft or housing seat
- cage damage from running beyond the limiting speed
Selection pitfalls — read before you substitute
- At 440 mm bore, C3 clearance is the safe choice when interference fits plus temperature rise consume the CN clearance; a hot tight bearing with no residual clearance fails fast.
- Deep-groove geometry tolerates only minutes of misalignment; if the 540 mm housing bore cannot be aligned, move to a self-aligning bearing rather than shimming 61888-MA.
- The MA suffix on 61888-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 22500 g quoted mass includes the heavier cage.
- Open 61888-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 61888-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 440 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 61888-MA?
The SKF 61888 MA measures 440 mm bore × 540 mm OD × 46 mm width (17.323 × 21.26 × 1.811 in), mass about 22500 g. It is open, with no shields or seals.
How does the bore code in 61888 work?
The final two digits of 61888 are bore code 88, multiplied by 5 to give 440 mm.
How heavy is 61888-MA?
Catalogue mass is 22500 g for 61888 MA; seal and cage executions of the same envelope differ by a few grams.
What load can 61888-MA take?
Catalogue values for 61888 MA: dynamic C 255 kN, static C0 440 kN, fatigue limit Pu 8.5 kN. Use C in life calculation and C0 for static checks at 440 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.