61811-2RS bearing: complete specifications & equivalents
The 61811-2RS is a ISO 15 radial bearing sized 55 x 72 x 9 mm (bore x OD x width) with 2RS sealing. Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Bore diameter d | 55 mm |
| Outer diameter D | 72 mm |
| Width B | 9 mm |
| Material | GCr15 |
| Seal / shield | 2RS |
| 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 |
| Limiting speed (mechanical) | 5300 rpm |
| Operating temperature | -30 to +110 °C |
| Mass | 83 g |
| Manufacturer designation | SKF 61811-2RS1 |
| 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 | 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 | 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) | 12 of 39 |
| Bore above smallest 61800-series size | 45 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61811-ZZ | GENERIC-ISO | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 55×72×9 mm envelope per ISO 15; seal variant differs (2RS 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 61811-2RS model number is decoded
In the 61800-series (ISO 15 diameter series 8) the last two digits encode the bore: 61811 carries bore code 11 = 55 mm. Outside diameter 72 mm and width 9 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 55 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude.
Typical equipment & failure modes
Common applications
- clutch and transmission assemblies
- robotics and automation joints
- lay shafts and idler shafts
- textile machinery
Known failure patterns
- seal-lip hardening and loss of pre-grease in sustained high-temperature service
- grease-life expiry in the sealed-for-life cavity (no relubrication path)
- electrical pitting in VFD-driven motors without grounding protection
- raceway smearing under marginal lubrication at start-up
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.
- Contact seals add drag and heat: 61811-2RS runs slower and cooler-limited than the open 61811; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.
- Never wash a sealed 61811-2RS in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.
- Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.
- SKF catalogues the contact-sealed version as 61811-2RS1 (older printings may read -2RS1); it is shipped pre-greased and its 5300 r/min limiting speed is set by seal-lip drag and grease life versus the open bearing's 19000 r/min thermal reference speed.
- 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 61811-2RS bearing?
A 61811-2RS 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 contact rubber seals and is normally pre-greased.
How does the 61811 bore code work?
The last two digits of 61811 are bore code 11, giving 11 × 5 = 55 mm bore. The 72 mm outside diameter and 9 mm width follow the ISO 15 diameter series, not the bore code alone.
What does the 2RS suffix on 61811-2RS mean?
2RS means two contact elastomer seals, one each side, usually over a lifetime grease fill. Sealing against dust and moisture is better than ZZ shields, but the lip drag lowers the speed and temperature ceiling.
How does the 61800 compare with other series at the same 55 mm bore?
618 is an extra-thin section: 72×9 mm, only 8.5 mm radial section at 55 mm bore, far smaller than a 6211, for space-limited layouts at the cost of load rating and misalignment tolerance.
What is the SKF designation and catalogue data for 61811-2RS?
In the SKF Rolling Bearings catalogue this size is listed as 61811-2RS1 — two contact elastomer seals over a lifetime grease fill, 55×72×9 mm per ISO 15. Quoted values: C 9.04 kN, C0 8.8 kN, Pu 0.375 kN, limiting speed 5300 r/min, mass 83 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 61811-2RS.
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.