61948 bearing: complete specifications & equivalents
The 61948 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 |
|---|---|
| Bore diameter d | 240 mm |
| Outer diameter D | 320 mm |
| Width B | 38 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN / C3 available |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| 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) | 2400 rpm |
| Operating temperature | -40 to +150 °C |
| Mass | 7300 g |
| Manufacturer designation | SKF 61948 |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018) |
| Last verified | 2026-09-24 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018)) · extracted 2026-09-24
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 | 10 mm |
| Largest outer diameter in 61900-series | 420 mm |
| Width range across 61900-series | 6–56 mm |
| Bore position in 61900-series (smallest first) | 32 of 35 |
| Bore above smallest 61900-series size | 230 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61948 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; brand-specific OEM equivalents (NSK/FAG/NTN) pending multi-source data. |
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 model number is decoded
In the 61900-series (ISO 15 diameter series 9) the last two digits encode the bore: 61948 carries bore code 48 = 240 mm. Outside diameter 320 mm and width 38 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 240 mm shaft, typical catalogue practice is a m6 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude.
Typical equipment & failure modes
Common applications
- textile machinery
- packaging machinery
- space-constrained gearboxes
- clutch and transmission assemblies
Known failure patterns
- contamination wear from dust and dirt ingress through the open arrangement
- lubricant starvation when no regreasing interval is maintained
- electrical pitting in VFD-driven motors without grounding protection
- raceway smearing under marginal lubrication at start-up
Selection pitfalls — read before you substitute
- Mount this 240 mm bore bearing by heating the inner ring (induction heater, max 120 °C) — never drive it home through the outer ring or balls, that brinells the raceways.
- The 619xx thin section (40.0 mm section height at 240 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.
- The open 61948 has no lubricant retention: grease escapes and contaminants migrate straight into the 240×320×38 mm raceway, so specify a sealed arrangement for dusty or washdown duty.
- Open bearings tolerate the highest speeds in the 61900-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61948 units.
- A 240 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.
- The open 61948 needs external sealing and application-supplied lubrication; in the SKF catalogue the protected variants are separate order numbers 61948-2Z (shields) and 61948-2RSH (contact seals), not suffix-free 61948.
- The 159/200 kN ratings here are SKF Explorer-class figures from catalogue PUB BU/P1 17000/1 EN (Oct 2018); SKF can revise internal geometry and ratings without changing the designation, so treat the catalogue version and date as part of the specification and re-verify for critical drives.
Frequently asked questions
What are the dimensions of a 61948 bearing?
A 61948 deep-groove ball bearing has a 240 mm bore, 320 mm outer diameter and 38 mm width (9.449 × 12.598 × 1.496 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields.
How does the 61948 bore code work?
The last two digits of 61948 are bore code 48, giving 48 × 5 = 240 mm bore. The 320 mm outside diameter and 38 mm width follow the ISO 15 diameter series, not the bore code alone.
What does no suffix on 61948 mean?
A bare 61948 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication.
How does the 61900 compare with other series at the same 240 mm bore?
619 is a thin section one step above 618: 320×38 mm with a 40.0 mm radial section at 240 mm bore; a 6248 on the same bore is substantially larger and more heavily rated.
What is the SKF designation and catalogue data for 61948?
In the SKF Rolling Bearings catalogue this size is listed as 61948 — the open (unsealed) execution, 240×320×38 mm per ISO 15. Quoted values: C 159 kN, C0 200 kN, Pu 5.1 kN, limiting speed 2400 r/min, mass 7300 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 61948.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018) on 2026-09-24. Read our editorial & correction policy.