61820-RSR bearing: complete specifications & equivalents
The 61820-RSR is a ISO 15 radial bearing sized 100 x 125 x 13 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 | 100 mm |
| Outer diameter D | 125 mm |
| Width B | 13 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 | 17.8 kN |
| Basic static load rating C0 | 18.3 kN |
| Fatigue load limit Pu | 0.95 kN |
| Reference speed (thermal) | 10000 rpm |
| Limiting speed (mechanical) | 5300 rpm |
| Operating temperature | -30 to +120 °C |
| Mass | 320 g |
| Manufacturer designation | SKF 61820-2RZ |
| 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 | 3.937 in |
|---|---|
| Outer diameter D | 4.921 in |
| Width B | 0.512 in |
| ISO bore code | 20 |
| Radial section height (D−d)/2 | 12.5 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) | 31 of 74 |
| Bore above smallest 61800-series size | 99 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61820-2RS-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 100×125×13 mm envelope per ISO 15; seal variant (RSR vs 2RS) and load ratings differ — confirm sealing and rating before substituting. |
| 61820-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 100×125×13 mm envelope per ISO 15; seal variant (RSR vs OPEN) and load ratings differ — confirm sealing and rating before substituting. |
| 61820-RSR-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 100×125×13 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 61820-ZZ | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 100×125×13 mm envelope per ISO 15; seal variant (RSR vs ZZ) and load ratings differ — confirm sealing and rating before substituting. |
| 61820-2RS-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 100×125×13 mm envelope per ISO 15; seal variant (RSR vs 2RS) and load ratings differ — confirm sealing and rating before substituting. |
| 61820-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 100×125×13 mm envelope per ISO 15; seal variant (RSR vs OPEN) and load ratings differ — confirm sealing and rating before substituting. |
| 61820-RSR-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 100×125×13 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 61820-ZZ-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 100×125×13 mm envelope per ISO 15; seal variant (RSR 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 61820-RSR model number is decoded
61820-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 20 by five gives the 100 mm bore; the 125 mm outside diameter and 13 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 100 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 61820-2RZ.
Typical equipment & failure modes
Common applications
- space-constrained gearboxes
- clutch and transmission assemblies
- robotics and automation joints
- lay shafts and idler shafts
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
- fretting corrosion on a loose shaft seat
- cage damage from operation beyond the limiting speed
Selection pitfalls — read before you substitute
- At 100 mm bore the ring mass is significant: heat 61820 on an induction heater (max 120 °C), never over an open flame, and plan puller access or a withdrawal sleeve now for the day it has to come off again.
- The 618xx thin section at 100 mm bore has only a 12.5 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 6220.
- The low-drag lip of 61820-RSR barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.
- The non-contact lip of 61820-RSR does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 100 mm bore position before relying on it as sealed-for-life.
- 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.
- Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 13 mm-wide ring of 61820-RSR drags the lip and overheats it.
- SKF catalogues the low-friction seal as 61820-2RZ (suffix -2RSL or -2RZ): a non-contact elastomer lip that runs near the open 5300 r/min limiting speed, closer to the open bearing's 10000 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 17.8/18.3 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 61820-RSR bearing?
A 61820-RSR deep-groove ball bearing has a 100 mm bore, 125 mm outer diameter and 13 mm width (3.937 × 4.921 × 0.512 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals.
How does the 61820 bore code work?
The last two digits of 61820 are bore code 20, giving 20 × 5 = 100 mm bore. The 125 mm outside diameter and 13 mm width follow the ISO 15 diameter series, not the bore code alone.
What does the RSR suffix on 61820-RSR mean?
RSR means two low-friction non-contact rubber seals. They keep coarse debris out with minimal drag (speed close to the open bearing) but are not liquid-tight; use -2RS contact seals for wet or fine-dust environments.
How does the 61800 compare with other series at the same 100 mm bore?
618 is an extra-thin section: 125×13 mm, only 12.5 mm radial section at 100 mm bore, far smaller than a 6220, for space-limited layouts at the cost of load rating and misalignment tolerance.
What is the SKF designation and catalogue data for 61820-RSR?
In the SKF Rolling Bearings catalogue this size is listed as 61820-2RZ — two low-friction non-contact elastomer seals, 100×125×13 mm per ISO 15. Quoted values: C 17.8 kN, C0 18.3 kN, Pu 0.95 kN, limiting speed 5300 r/min, mass 320 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 61820-RSR.
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.