61811-RSR bearing: complete specifications & equivalents
The 61811-RSR is a ISO 15 radial bearing sized 55 x 72 x 9 mm (bore x OD x width) with RSR sealing. Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 55 mm |
| Outer diameter D | 72 mm |
| Width B | 9 mm |
| Material | GCr15 |
| Seal / shield | RSR |
| Internal clearance | CN / C3 available |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 9.04 kN |
| Basic static load rating C0 | 8.8 kN |
| Fatigue load limit Pu | 0.375 kN |
| Reference speed (thermal) | 19000 rpm |
| Limiting speed (mechanical) | 9500 rpm |
| Operating temperature | -30 to +120 °C |
| Mass | 83 g |
| Manufacturer designation | SKF 61811-2RZ |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018) |
| Last verified | 2026-09-25 |
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 | 2.165 in |
|---|---|
| Outer diameter D | 2.835 in |
| Width B | 0.354 in |
| ISO bore code | 11 |
| Radial section height (D−d)/2 | 8.5 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) | 22 of 74 |
| Bore above smallest 61800-series size | 54 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61811-2RS-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 55×72×9 mm envelope per ISO 15; seal variant differs (RSR vs 2RS) — confirm sealing suits the duty. |
| 61811-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 55×72×9 mm envelope per ISO 15; seal variant differs (RSR vs OPEN) — confirm sealing suits the duty. |
| 61811-RSR-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. |
| 61811-ZZ | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 55×72×9 mm envelope per ISO 15; seal variant differs (RSR vs ZZ) — confirm sealing suits the duty. |
| 61811-2RS-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 55×72×9 mm envelope per ISO 15; seal variant differs (RSR vs 2RS) — confirm sealing suits the duty. |
| 61811-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 55×72×9 mm envelope per ISO 15; seal variant differs (RSR vs OPEN) — confirm sealing suits the duty. |
| 61811-RSR-NTN | NTN | 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. |
| 61811-ZZ-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 55×72×9 mm envelope per ISO 15; seal variant differs (RSR 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 61811-RSR model number is decoded
61811-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 11 by five gives the 55 mm bore; the 72 mm outside diameter and 9 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 55 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. SKF's low-friction seal suffix is 2RSL/2RZ (this page's industry-neutral spelling is -RSR); catalogue number 61811-2RZ.
Typical equipment & failure modes
Common applications
- clutch and transmission assemblies
- robotics and automation joints
- lay shafts and idler shafts
- textile machinery
Known failure patterns
- ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)
- lip-lubricant starvation if the bearing runs dry for extended periods
- 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
- Temperature rise and interference fits consume internal clearance on this 55 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 61811 with C3 for those conditions.
- The 618xx thin section at 55 mm bore has only a 8.5 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 6211.
- RSR low-friction seals on 61811-RSR run faster than contact-seal 61811-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61811-2RS instead.
- The non-contact lip of 61811-RSR does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 55 mm bore position before relying on it as sealed-for-life.
- Suffixes stack in a defined order — clearance follows the seal code, e.g. 61811-C3. No clearance suffix means normal CN clearance.
- Measure the shaft, do not trust the drawing: a 55 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 61811-RSR.
- SKF catalogues the low-friction seal as 61811-2RZ (suffix -2RSL or -2RZ): a non-contact elastomer lip that runs near the open 9500 r/min limiting speed, closer to the open bearing's 19000 r/min reference than the contact-seal version. It keeps coarse debris out without the drag of a contact seal, but is not liquid-tight — use 2RSH for wet or fine-dust positions.
- The 9.04/8.8 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 61811-RSR bearing?
A 61811-RSR deep-groove ball bearing has a 55 mm bore, 72 mm outer diameter and 9 mm width (2.165 × 2.835 × 0.354 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals.
What internal clearance does 61811-RSR have?
Unless a clearance suffix says otherwise, 61811-RSR is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61811 and verify the residual clearance after mounting.
How should 61811-RSR be mounted?
Apply the mounting force to the ring being fitted: on a 55 mm shaft seat the press load must pass through the inner-ring face only. Induction heating of the inner ring (max 120 °C) is the clean method at this size. Never strike the outer ring, the cage or the seals.
What lubrication does 61811-RSR need?
61811-RSR is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 61811 with a housing grease fitting instead.
What is the SKF designation and catalogue data for 61811-RSR?
In the SKF Rolling Bearings catalogue this size is listed as 61811-2RZ — two low-friction non-contact elastomer seals, 55×72×9 mm per ISO 15. Quoted values: C 9.04 kN, C0 8.8 kN, Pu 0.375 kN, limiting speed 9500 r/min, mass 83 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 61811-RSR.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018) on 2026-09-25. Read our editorial & correction policy.