61804-RSR bearing: complete specifications & equivalents
The 61804-RSR is a ISO 15 radial bearing sized 20 x 32 x 7 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 | 20 mm |
| Outer diameter D | 32 mm |
| Width B | 7 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 | 4.03 kN |
| Basic static load rating C0 | 2.32 kN |
| Fatigue load limit Pu | 0.104 kN |
| Reference speed (thermal) | 45000 rpm |
| Limiting speed (mechanical) | 22000 rpm |
| Operating temperature | -30 to +120 °C |
| Mass | 18 g |
| Manufacturer designation | SKF 61804-2RZ |
| 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 | 0.787 in |
|---|---|
| Outer diameter D | 1.26 in |
| Width B | 0.276 in |
| ISO bore code | 04 |
| Radial section height (D−d)/2 | 6 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) | 15 of 74 |
| Bore above smallest 61800-series size | 19 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61804-2RS-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 20×32×7 mm envelope per ISO 15; seal variant differs (RSR vs 2RS) — confirm sealing suits the duty. |
| 61804-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 20×32×7 mm envelope per ISO 15; seal variant differs (RSR vs OPEN) — confirm sealing suits the duty. |
| 61804-ZZ-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 20×32×7 mm envelope per ISO 15; seal variant differs (RSR vs ZZ) — confirm sealing suits the duty. |
| 61804-2RS-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 20×32×7 mm envelope per ISO 15; seal variant differs (RSR vs 2RS) — confirm sealing suits the duty. |
| 61804-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 20×32×7 mm envelope per ISO 15; seal variant differs (RSR vs OPEN) — confirm sealing suits the duty. |
| 61804-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. |
| 61804-ZZ | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 20×32×7 mm envelope per ISO 15; seal variant differs (RSR vs ZZ) — confirm sealing suits the duty. |
| 61804-2RS-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 20×32×7 mm envelope per ISO 15; seal variant differs (RSR vs 2RS) — confirm sealing suits the duty. |
| 61804-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 20×32×7 mm envelope per ISO 15; seal variant differs (RSR vs OPEN) — confirm sealing suits the duty. |
| 61804-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. |
| 61804-ZZ-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 20×32×7 mm envelope per ISO 15; seal variant differs (RSR vs ZZ) — confirm sealing suits the duty. |
| W61804-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF stainless execution W 61804-2RS1 shares the 20×32×7 mm envelope but rates differently (4.03/2.32 kN vs 3.12/2.08 kN) — not a load-rating equivalent. |
| W61804-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF stainless execution W 61804-2Z shares the 20×32×7 mm envelope but rates differently (4.03/2.32 kN vs 3.12/2.08 kN) — not a load-rating equivalent. |
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 61804-RSR model number is decoded
In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61804 carries bore code 04 = 20 mm. Outside diameter 32 mm and width 7 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 20 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. SKF's low-friction seal suffix is 2RSL/2RZ (this page's industry-neutral spelling is -RSR); catalogue number 61804-2RZ.
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
- A 20 mm shaft for 61804 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.
- Only 6.0 mm of radial section separates bore and OD on the 618xx series at 20 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6204.
- RSR low-friction seals on 61804-RSR run faster than contact-seal 61804-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61804-2RS instead.
- The non-contact lip of 61804-RSR does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 20 mm bore position before relying on it as sealed-for-life.
- Never mix components between two 61804-RSR units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.
- Deep-groove ball bearings tolerate only minutes of misalignment; if the 32 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 61804-RSR.
- SKF catalogues the low-friction seal as 61804-2RZ (suffix -2RSL or -2RZ): a non-contact elastomer lip that runs near the open 22000 r/min limiting speed, closer to the open bearing's 45000 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 4.03/2.32 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 61804-RSR bearing?
A 61804-RSR deep-groove ball bearing has a 20 mm bore, 32 mm outer diameter and 7 mm width (0.787 × 1.26 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals.
Are 61804 bearings from different brands interchangeable?
For boundary dimensions, yes: every brand's 61804 uses the same ISO 15 envelope (20×32×7 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar).
What internal clearance does 61804-RSR have?
Unless a clearance suffix says otherwise, 61804-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 61804 and verify the residual clearance after mounting.
How should 61804-RSR be mounted?
Apply the mounting force to the ring being fitted: on a 20 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals.
What is the SKF designation and catalogue data for 61804-RSR?
In the SKF Rolling Bearings catalogue this size is listed as 61804-2RZ — two low-friction non-contact elastomer seals, 20×32×7 mm per ISO 15. Quoted values: C 4.03 kN, C0 2.32 kN, Pu 0.104 kN, limiting speed 22000 r/min, mass 18 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 61804-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.