61909 bearing: complete specifications & equivalents
The 61909 is a ISO 15 radial bearing sized 45 x 68 x 12 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Bore diameter d | 45 mm |
| Outer diameter D | 68 mm |
| Width B | 12 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 | 14 kN |
| Basic static load rating C0 | 10.8 kN |
| Fatigue load limit Pu | 0.465 kN |
| Reference speed (thermal) | 20000 rpm |
| Limiting speed (mechanical) | 13000 rpm |
| Operating temperature | -40 to +150 °C |
| Mass | 140 g |
| Manufacturer designation | SKF 61909 |
| 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 | 1.772 in |
|---|---|
| Outer diameter D | 2.677 in |
| Width B | 0.472 in |
| ISO bore code | 09 |
| Radial section height (D−d)/2 | 11.5 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) | 10 of 35 |
| Bore above smallest 61900-series size | 35 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61909-ZZ | GENERIC-ISO | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 45×68×12 mm envelope per ISO 15; seal variant differs (OPEN vs ZZ) — confirm sealing suits the duty. |
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 61909 model number is decoded
In the 61900-series (ISO 15 diameter series 9) the last two digits encode the bore: 61909 carries bore code 09 = 45 mm. Outside diameter 68 mm and width 12 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 45 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the SKF catalogue this open execution carries the bare designation; protected variants are ordered separately as -2Z and -2RSH.
Typical equipment & failure modes
Common applications
- clutch and transmission assemblies
- robotics and automation joints
- lay shafts and idler shafts
- textile machinery
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
- At a 45 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 61909; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.
- The 619xx thin section (11.5 mm section height at 45 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.
- The open 61909 has no lubricant retention: grease escapes and contaminants migrate straight into the 45×68×12 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 61909 units.
- Deep-groove ball bearings tolerate only minutes of misalignment; if the 68 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 61909.
- The open 61909 needs external sealing and application-supplied lubrication; in the SKF catalogue the protected variants are separate order numbers 61909-2Z (shields) and 61909-2RSH (contact seals), not suffix-free 61909.
- The 14/10.8 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 61909 bearing?
A 61909 deep-groove ball bearing has a 45 mm bore, 68 mm outer diameter and 12 mm width (1.772 × 2.677 × 0.472 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields. Geometry-based estimated mass is about 125 g for a steel-cage unit; catalogue masses vary slightly with seal and cage design.
How does the 61909 bore code work?
The last two digits of 61909 are bore code 09, giving 09 × 5 = 45 mm bore. The 68 mm outside diameter and 12 mm width follow the ISO 15 diameter series, not the bore code alone.
What does no suffix on 61909 mean?
A bare 61909 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 45 mm bore?
619 is a thin section one step above 618: 68×12 mm with a 11.5 mm radial section at 45 mm bore; a 6209 on the same bore is substantially larger and more heavily rated.
What is the SKF designation and catalogue data for 61909?
In the SKF Rolling Bearings catalogue this size is listed as 61909 — the open (unsealed) execution, 45×68×12 mm per ISO 15. Quoted values: C 14 kN, C0 10.8 kN, Pu 0.465 kN, limiting speed 13000 r/min, mass 140 g. Brand suffixes (2Z, 2RSH) differ from the industry-neutral spelling 61909.
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.