W61804-2RS bearing: complete specifications & equivalents

The W61804-2RS is a ISO 15 radial bearing sized 20 x 32 x 7 mm (bore x OD x width) with 2RS sealing. Verify dimensions against the official catalog before ordering.

Bearing dimension schematic Front view shows outer diameter D and bore d; side section shows width B. D = 32 mm d = 20 B = 7 mm side section front view
Principal dimensions: bore d 20 mm, outer diameter D 32 mm, width B 7 mm. Schematic, not to scale.

Specification table

ParameterValue
Brand SKF
Bore diameter d 20 mm
Outer diameter D 32 mm
Width B 7 mm
Material SS440C
Seal / shield 2RS
Internal clearance CN
Tolerance class P0
Cage steel, stamped ribbon (J-type)
Basic dynamic load rating C 3.12 kN
Basic static load rating C0 2.08 kN
Fatigue load limit Pu 0.09 kN
Limiting speed (mechanical) 13000 rpm
Operating temperature -40 to +120 °C
Mass 17 g
Manufacturer designation W 61804-2RS1
Standard ISO 15
Catalog version SKF PUB BU/P1 17000/1 EN (Oct 2018)
Last verified 2026-09-27

Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018)) · extracted 2026-09-27

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 modelBrandMatch levelNote
61804-ZZ NSK partial
Main dimensions match; tolerances, seals or internal clearance differ.
NSK NSK 6804ZZ shares the 20×32×7 mm envelope but carries different catalogue ratings (3.12/2.08 kN vs 4.4/2.47 kN) — the stainless execution is not a load-rating equivalent.
W61804-ZZ SKF full
Dimensions and internal design equivalent — standard interchange.
Same 20×32×7 mm envelope and equivalent catalogue ratings; W 61804-2Z is the two non-contact shields execution of this size — boundary dimensions interchangeable, only the seal/shield/cage execution differs.
61804 SKF partial
Main dimensions match; tolerances, seals or internal clearance differ.
SKF SKF 61804 shares the 20×32×7 mm envelope but carries different catalogue ratings (3.12/2.08 kN vs 4.03/2.32 kN) — the stainless execution is not a load-rating equivalent.
61804-2RS SKF partial
Main dimensions match; tolerances, seals or internal clearance differ.
SKF SKF 61804-2RS1 shares the 20×32×7 mm envelope but carries different catalogue ratings (3.12/2.08 kN vs 4.03/2.32 kN) — the stainless execution is not a load-rating equivalent.
61804-RSR SKF partial
Main dimensions match; tolerances, seals or internal clearance differ.
SKF SKF 61804-2RZ shares the 20×32×7 mm envelope but carries different catalogue ratings (3.12/2.08 kN vs 4.03/2.32 kN) — the stainless execution is 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 W61804-2RS model number is decoded

The W prefix denotes SKF stainless steel deep-groove bearings (X108CrMo17 / AISI 440C class rings). In the 61800-series, the last two digits encode the bore: 61804 carries code 04 = 20 mm (code × 5). Envelope 20×32×7 mm (0.787×1.26×0.276 in), C 3.12 kN, C0 2.08 kN, Pu 0.09 kN; limiting speed 13000 r/min and mass 17 g. SKF catalogues the sealed execution as W 61804-2RS1: two contact elastomer lips (2RS1/2RSH spelling) over a lifetime grease fill; the lips add drag, and no reference (thermal) speed is published. Stainless is chosen for corrosion and washdown duty, not for extra load — the same-envelope chrome-steel bearing rates higher.

Typical equipment & failure modes

Common applications

  • washdown-duty equipment
  • chemical and marine atmospheres
  • medical and laboratory devices
  • small pumps handling corrosive media

Known failure patterns

  • seal and grease failure before the rings corrode in sustained washdown service
  • surface staining and pitting when even the stainless steel is left unlubricated in salty or acidic duty
  • contact-seal lip hardening and pre-grease loss after long high-temperature service
  • grease-life expiry inside the sealed-for-life cavity, which has no relubrication path

Selection pitfalls — read before you substitute

  • The stainless steel is martensitic and MAGNETIC; do not reject W61804-2RS over magnetism — only austenitic grades are non-magnetic, and those are too soft for bearing raceways.
  • Stainless bearings carry lower load ratings than chrome steel of the same envelope: W61804-2RS is quoted at C 3.12 kN versus the 7 mm-wide 52100 version — do not swap on dimensions alone.
  • Food, pharmaceutical and washdown positions need food-grade grease (e.g. NSF H1 registered) inside W61804-2RS; standard fill is industrial grease unless specified otherwise.
  • Corrosion resistance depends on clean, undamaged surfaces: never weld near W61804-2RS or scratch the raceways during mounting, since the damaged spot starts corrosion.
  • Catalogue ratings for W61804-2RS (C 3.12 kN, C0 2.08 kN) are SKF figures from PUB BU/P1 17000; geometry revisions can change ratings without changing the designation, so keep the catalogue edition with the specification.
  • Fillet radii must clear the W61804-2RS chamfer so the 7 mm-wide ring seats square; an oversized shaft radius creates point contact on the ring face.

Frequently asked questions

What are the dimensions of the stainless W61804-2RS?

SKF W 61804-2RS1 measures 20×32×7 mm (0.787×1.26×0.276 in), about 17 g, C 3.12 kN.

What does the W in W 61804-2RS1 mean?

W is the SKF prefix for stainless steel deep-groove bearings (rings in X108CrMo17 / AISI 440C class); the rest of the designation follows the normal series and bore rules.

What grease is supplied in W61804-2RS?

Sealed units are pre-greased for life; for food or pharmaceutical duty order (or re-grease before service) with an NSF H1 registered food-grade grease.

Are W stainless bearings waterproof?

No — the stainless rings resist moisture and weak chemicals far better than 52100 chrome steel, but salt spray, strong chlorides and unlubricated washdown duty can still corrode W61804-2RS; add seals and food-grade grease for wet positions.

Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018) on 2026-09-27. Read our editorial & correction policy.