3204-A-2RS1 bearing: complete specifications & equivalents
The 3204-A-2RS1 is a ISO 15 radial bearing sized 20 x 47 x 20.6 mm (bore x OD x width) with 2RS sealing. Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 20 mm |
| Outer diameter D | 47 mm |
| Width B | 20.6 mm |
| Material | GCr15 |
| Seal / shield | 2RS |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 20.4 kN |
| Basic static load rating C0 | 12.9 kN |
| Fatigue load limit Pu | 0.55 kN |
| Limiting speed (mechanical) | 10000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 160 g |
| Manufacturer designation | 3204 A-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 & 3200-series range
| Bore d | 0.787 in |
|---|---|
| Outer diameter D | 1.85 in |
| Width B | 0.811 in |
| ISO bore code | 04 |
| Radial section height (D−d)/2 | 13.5 mm |
| Smallest bore in 3200-series | 10 mm |
| Largest outer diameter in 3200-series | 200 mm |
| Width range across 3200-series | 14–69.8 mm |
| Bore position in 3200-series (smallest first) | 5 of 22 |
| Bore above smallest 3200-series size | 10 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 3204-A | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 20×47×20.6 mm envelope with catalogue ratings within 10 %; 3204 A is the stamped steel cage, open arrangement execution of this size — boundary dimensions interchangeable, execution differs. |
| 3204-ATN9 | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 20×47×20.6 mm envelope with catalogue ratings within 10 %; 3204 ATN9 is the glass-fibre PA66 cage, open arrangement execution of this size — boundary dimensions interchangeable, execution differs. |
| 3204-A-2Z | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 20×47×20.6 mm envelope with catalogue ratings within 10 %; 3204 A-2Z is the stamped steel cage, shields (-2Z) execution of this size — boundary dimensions interchangeable, execution differs. |
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 3204-A-2RS1 model number is decoded
3204 A-2RS1 is the capped double-row angular-contact ball bearing for a 20 mm shaft, 20×47×20.6 mm, greased and sealed (or shielded) for life at the SKF works. A on this double-row bearing means no filling slots, so both ball rows retain their full complement. -2RS1 marks a contact NBR elastomer seal on each side, riding the inner ring: better fine-dust and moisture protection than a shield at the cost of seal drag and a lower speed ceiling. Envelope 20×47×20.6 mm (0.787×1.85×0.811 in), 13.5 mm radial section height, C 20.4 kN, C0 12.9 kN, Pu 0.55 kN.SKF publishes only the 10,000 r/min limiting speed for this execution, catalogue mass 160 g. The 0.55 kN fatigue load limit is the equivalent-load floor for long-life adjustment; with 20.4/12.9 kN ratings and 160 g mass this execution carries about 1.02 kN of C per millimetre of bore. Selection figures for 3204 A-2RS1: the static-to-dynamic ratio C0/C is 0.63, Pu 0.55 kN is about 3 % of C, and catalogue mass works out to roughly 8 g per millimetre of bore. Speed-ratio note for this exact unit: no thermal reference speed is listed (seal/grease life governs), so the 10,000 r/min limiting value is the single published ceiling. Contact-seal execution note: the two NBR -2RS1 lips ride the inner-ring lands, sealing the factory grease against moisture and fine dust; the lips add running torque and set the lower limiting speed printed for this size, and the sealed cavity is maintenance-free by design (no relubrication path). The A-2Z shielded order number is the low-drag alternative for cleaner positions.
Typical equipment & failure modes
Common applications
- conveyor idlers and small drives
- domestic-appliance motors
- maintenance-free small gear and pump shafts
Known failure patterns
- contamination trapped for life when a capped bearing is mounted with dirty hands or tools
- contact-seal lip hardening and grease-life expiry after long high-temperature service
- seal-lip wear and grease loss after fine abrasive dust reaches the lip contact
- tilted mounting that loads one double row more heavily than the other
- raceway staining from water in the lubricant during idle periods
- rolling-contact fatigue spalling after the rated L10 life is exceeded
Selection pitfalls — read before you substitute
- Open 3204 and capped 3204-A-2RS1 share the 20×47×20.6 mm envelope and 20.4/12.9 kN ratings — the choice is maintenance access and contamination, not capacity.
- The contact NBR seals add drag and a lower speed ceiling: no relubrication is provided for, so mounting cleanliness decides much of the real grease life.
- Never wash 3204-A-2RS1 in solvent: the lifetime grease fill cannot be replaced once flushed out.
- Fit and fillet rules are unchanged from the open double-row 3204: k5 on a 20 mm rotating shaft, radii clearing the chamfer.
- Catalogue ratings are SKF PUB BU/P1 17000 figures for 3204 A-2RS1 as the double contactsealed execution; the other order numbers of the 3204 size are different products and may carry different ratings — always quote the full designation when purchasing.
Frequently asked questions
What are the dimensions and catalogue data of 3204-A-2RS1?
3204 A-2RS1 measures 20 mm bore × 47 mm OD × 20.6 mm width (0.787 × 1.85 × 0.811 in), mass about 160 g. SKF 17000 ratings: C 20.4 kN, C0 12.9 kN, Pu 0.55 kN, SKF publishes only the 10,000 r/min limiting speed for this execution.
What does the A-2RS1 suffix mean?
A on this double-row bearing means no filling slots, so both ball rows retain their full complement. -2RS1 marks a contact NBR elastomer seal on each side, riding the inner ring: better fine-dust and moisture protection than a shield at the cost of seal drag and a lower speed ceiling.
Is 3204-A-2RS1 sealed for life?
Yes — the two -2RS1 contact NBR seals enclose a lifetime grease fill; there is no relubrication provision, and the seals cap the limiting speed at 10,000 r/min.
What is the difference between 3204 A-2Z and A-2RS1?
Both share the double-row A geometry, dimensions and ratings; A-2Z uses non-contact metal shields (lower drag, higher speed, dust protection), A-2RS1 uses contact NBR rubber seals (better moisture and fine-dust protection, lower speed ceiling and more drag).
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.