61901 bearing: complete specifications & equivalents
The 61901 is a ISO 15 radial bearing sized 12 x 24 x 6 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Bore diameter d | 12 mm |
| Outer diameter D | 24 mm |
| Width B | 6 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 | 2.91 kN |
| Basic static load rating C0 | 1.46 kN |
| Fatigue load limit Pu | 0.062 kN |
| Reference speed (thermal) | 67000 rpm |
| Limiting speed (mechanical) | 40000 rpm |
| Operating temperature | -40 to +150 °C |
| Mass | 11 g |
| Manufacturer designation | SKF 61901 |
| 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 | 0.472 in |
|---|---|
| Outer diameter D | 0.945 in |
| Width B | 0.236 in |
| ISO bore code | 01 |
| Radial section height (D−d)/2 | 6 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) | 2 of 35 |
| Bore above smallest 61900-series size | 2 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61901 | 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 61901 model number is decoded
In the 61900-series (ISO 15 diameter series 9) the last two digits encode the bore: 61901 carries bore code 01 = 12 mm. Codes 00–03 follow the 10/12/15/17 mm exception table rather than code × 5. Outside diameter 24 mm and width 6 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 12 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude.
Typical equipment & failure modes
Common applications
- packaging machinery
- space-constrained gearboxes
- clutch and transmission assemblies
- robotics and automation joints
Known failure patterns
- contamination wear from dust and dirt ingress through the open arrangement
- lubricant starvation when no regreasing interval is maintained
- raceway smearing under marginal lubrication at start-up
- edge loading from shaft deflection or housing misalignment
Selection pitfalls — read before you substitute
- Bore codes 00–03 use the exception table: 61901 fits a 12 mm shaft — the code × 5 mnemonic does not apply below code 04 (it would imply 0 mm for code 00).
- The 619xx thin section (6.0 mm section height at 12 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.
- The open 61901 has no lubricant retention: grease escapes and contaminants migrate straight into the 12×24×6 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 61901 units.
- Shaft and housing fillets must clear the bearing chamfer so the 6 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.
- The open 61901 needs external sealing and application-supplied lubrication; in the SKF catalogue the protected variants are separate order numbers 61901-2Z (shields) and 61901-2RSH (contact seals), not suffix-free 61901.
- The 2.91/1.46 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 61901 bearing?
A 61901 deep-groove ball bearing has a 12 mm bore, 24 mm outer diameter and 6 mm width (0.472 × 0.945 × 0.236 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields.
Why does 61901 not follow the bore-code × 5 rule?
Codes 00–03 use the exception table (10, 12, 15 and 17 mm): 61901 with code 01 has a 12 mm bore. The code × 5 convention starts at code 04 (20 mm).
What does no suffix on 61901 mean?
A bare 61901 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 12 mm bore?
619 is a thin section one step above 618: 24×6 mm with a 6.0 mm radial section at 12 mm bore; a 6201 on the same bore is substantially larger and more heavily rated.
What is the SKF designation and catalogue data for 61901?
In the SKF Rolling Bearings catalogue this size is listed as 61901 — the open (unsealed) execution, 12×24×6 mm per ISO 15. Quoted values: C 2.91 kN, C0 1.46 kN, Pu 0.062 kN, limiting speed 40000 r/min, mass 11 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 61901.
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.