61809 bearing: complete specifications & equivalents
The 61809 is a ISO 15 radial bearing sized 45 x 58 x 7 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 45 mm |
| Outer diameter D | 58 mm |
| Width B | 7 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 | 6.63 kN |
| Basic static load rating C0 | 6.1 kN |
| Fatigue load limit Pu | 0.26 kN |
| Reference speed (thermal) | 22000 rpm |
| Limiting speed (mechanical) | 14000 rpm |
| Operating temperature | -40 to +150 °C |
| Mass | 40 g |
| Manufacturer designation | SKF 61809 |
| 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 & 61800-series range
| Bore d | 1.772 in |
|---|---|
| Outer diameter D | 2.283 in |
| Width B | 0.276 in |
| ISO bore code | 09 |
| Radial section height (D−d)/2 | 6.5 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) | 20 of 74 |
| Bore above smallest 61800-series size | 44 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61809-2RS-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 45×58×7 mm envelope per ISO 15; seal variant differs (OPEN vs 2RS) — confirm sealing suits the duty. |
| 61809-NSK | NSK | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier. |
| 61809-RSR-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 45×58×7 mm envelope per ISO 15; seal variant differs (OPEN vs RSR) — confirm sealing suits the duty. |
| 61809-ZZ | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 45×58×7 mm envelope per ISO 15; seal variant differs (OPEN vs ZZ) — confirm sealing suits the duty. |
| 61809-2RS-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 45×58×7 mm envelope per ISO 15; seal variant (OPEN vs 2RS) and load ratings differ — confirm sealing and rating before substituting. |
| 61809-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 45×58×7 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 61809-RSR-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 45×58×7 mm envelope per ISO 15; seal variant (OPEN vs RSR) and load ratings differ — confirm sealing and rating before substituting. |
| 61809-ZZ-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 45×58×7 mm envelope per ISO 15; seal variant (OPEN vs ZZ) and load ratings differ — confirm sealing and rating before substituting. |
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 61809 model number is decoded
In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61809 carries bore code 09 = 45 mm. Outside diameter 58 mm and width 7 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
- electrical pitting in VFD-driven motors without grounding protection
- raceway smearing under marginal lubrication at start-up
Selection pitfalls — read before you substitute
- Sizes around 45 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 61809.
- Only 6.5 mm of radial section separates bore and OD on the 618xx series at 45 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6209.
- Storage matters for open bearings: 61809 leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.
- Open bearings tolerate the highest speeds in the 61800-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61809 units.
- The housing bore for the 58 mm OD should be round within IT7; an oval bore pinches the outer ring of 61809 and shows up later as two-point loaded raceway wear.
- Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 61800-series position can soften the mixture and leak — clean out the old fill before switching grease types.
- The open 61809 needs external sealing and application-supplied lubrication; in the SKF catalogue the protected variants are separate order numbers 61809-2Z (shields) and 61809-2RSH (contact seals), not suffix-free 61809.
- The 6.63/6.1 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 61809 bearing?
A 61809 deep-groove ball bearing has a 45 mm bore, 58 mm outer diameter and 7 mm width (1.772 × 2.283 × 0.276 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields.
How does the 61809 bore code work?
The last two digits of 61809 are bore code 09, giving 09 × 5 = 45 mm bore. The 58 mm outside diameter and 7 mm width follow the ISO 15 diameter series, not the bore code alone.
What does no suffix on 61809 mean?
A bare 61809 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 61800 compare with other series at the same 45 mm bore?
618 is an extra-thin section: 58×7 mm, only 6.5 mm radial section at 45 mm bore, far smaller than a 6209, for space-limited layouts at the cost of load rating and misalignment tolerance.
What is the SKF designation and catalogue data for 61809?
In the SKF Rolling Bearings catalogue this size is listed as 61809 — the open (unsealed) execution, 45×58×7 mm per ISO 15. Quoted values: C 6.63 kN, C0 6.1 kN, Pu 0.26 kN, limiting speed 14000 r/min, mass 40 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 61809.
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.