61844 bearing: complete specifications & equivalents
The 61844 is a ISO 15 radial bearing sized 220 x 270 x 24 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Bore diameter d | 220 mm |
| Outer diameter D | 270 mm |
| Width B | 24 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 | 78 kN |
| Basic static load rating C0 | 110 kN |
| Fatigue load limit Pu | 3 kN |
| Reference speed (thermal) | 4500 rpm |
| Limiting speed (mechanical) | 2800 rpm |
| Operating temperature | -40 to +150 °C |
| Mass | 2550 g |
| Manufacturer designation | SKF 61844 |
| 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 | 8.661 in |
|---|---|
| Outer diameter D | 10.63 in |
| Width B | 0.945 in |
| ISO bore code | 44 |
| Radial section height (D−d)/2 | 25 mm |
| Smallest bore in 61800-series | 10 mm |
| Largest outer diameter in 61800-series | 420 mm |
| Width range across 61800-series | 5–38 mm |
| Bore position in 61800-series (smallest first) | 33 of 39 |
| Bore above smallest 61800-series size | 210 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61844 | 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 61844 model number is decoded
In the 61800-series (ISO 15 diameter series 8) the last two digits encode the bore: 61844 carries bore code 44 = 220 mm. Outside diameter 270 mm and width 24 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 220 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
- rolling-contact fatigue spalling after the rated L10 life is exceeded
- brinelling from static overload or hammering during mounting
Selection pitfalls — read before you substitute
- Mount this 220 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 618xx thin section at 220 mm bore has only a 25.0 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6244.
- The open 61844 has no lubricant retention: grease escapes and contaminants migrate straight into the 220×270×24 mm raceway, so specify a sealed arrangement for dusty or washdown duty.
- 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 61844 units.
- Shaft and housing fillets must clear the bearing chamfer so the 24 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.
- The open 61844 needs external sealing and application-supplied lubrication; in the SKF catalogue the protected variants are separate order numbers 61844-2Z (shields) and 61844-2RSH (contact seals), not suffix-free 61844.
- The 78/110 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 61844 bearing?
A 61844 deep-groove ball bearing has a 220 mm bore, 270 mm outer diameter and 24 mm width (8.661 × 10.63 × 0.945 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields.
How does the 61844 bore code work?
The last two digits of 61844 are bore code 44, giving 44 × 5 = 220 mm bore. The 270 mm outside diameter and 24 mm width follow the ISO 15 diameter series, not the bore code alone.
What does no suffix on 61844 mean?
A bare 61844 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 220 mm bore?
618 is an extra-thin section: 270×24 mm, only 25.0 mm radial section at 220 mm bore, far smaller than a 6244, for space-limited layouts at the cost of load rating and misalignment tolerance.
What is the SKF designation and catalogue data for 61844?
In the SKF Rolling Bearings catalogue this size is listed as 61844 — the open (unsealed) execution, 220×270×24 mm per ISO 15. Quoted values: C 78 kN, C0 110 kN, Pu 3 kN, limiting speed 2800 r/min, mass 2550 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 61844.
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.