61948-MA bearing: complete specifications & equivalents
The 61948-MA is a ISO 15 radial bearing sized 240 x 320 x 38 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 240 mm |
| Outer diameter D | 320 mm |
| Width B | 38 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 159 kN |
| Basic static load rating C0 | 200 kN |
| Fatigue load limit Pu | 5.1 kN |
| Reference speed (thermal) | 4000 rpm |
| Limiting speed (mechanical) | 3200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 8550 g |
| Manufacturer designation | 61948 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 | 9.449 in |
|---|---|
| Outer diameter D | 12.598 in |
| Width B | 1.496 in |
| ISO bore code | 48 |
| Radial section height (D−d)/2 | 40 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) | 41 of 63 |
| Bore above smallest 61900-series size | 237 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61948-ZZ | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 240×320×38 mm envelope per ISO 15; seal variant differs (OPEN vs ZZ) — confirm sealing suits the duty. |
| 61948 | SKF | full Dimensions and internal design equivalent — standard interchange. | SKF SKF 61948 (open arrangement) shares the 240×320×38 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 61948-MA model number is decoded
In the 61900-series, the last two digits encode the bore: 61948 carries code 48 = 240 mm (code × 5). The envelope is 240×320×38 mm (9.449×12.598×1.496 in) with a 40.0 mm radial section height, C 159 kN, C0 200 kN and Pu 5.1 kN. The open 61948 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 3200 r/min, catalogue mass 8550 g. A thin section saves space but leaves little margin for misalignment or shaft deflection.
Typical equipment & failure modes
Common applications
- pulp and paper machinery
- marine deck machinery
- crusher auxiliary drives
- 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
- 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 5.1 kN; it feeds the equivalent-mean-load check, not the basic life calculation — do not substitute one for the other.
- At 240 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.
- The MA suffix on 61948-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 8550 g quoted mass includes the heavier cage.
- Open 61948-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 61948-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 240 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 61948-MA?
The SKF 61948 MA measures 240 mm bore × 320 mm OD × 38 mm width (9.449 × 12.598 × 1.496 in), mass about 8550 g. It is open, with no shields or seals.
How does the bore code in 61948 work?
The final two digits of 61948 are bore code 48, multiplied by 5 to give 240 mm.
What is the difference between 61948-MA and a same-bore 62-series bearing?
Section height differs: 61948-MA has a 40 mm radial section and C 159 kN; always match d, D and B — same bore alone never makes two bearings interchangeable.
Which fits should I use for 61948-MA?
With a rotating inner ring use roughly m6 on the shaft and H7 in the 320 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.