3305-A-2RS1 bearing: complete specifications & equivalents
The 3305-A-2RS1 is a ISO 15 radial bearing sized 25 x 62 x 25.4 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 | 25 mm |
| Outer diameter D | 62 mm |
| Width B | 25.4 mm |
| Material | GCr15 |
| Seal / shield | 2RS |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 32 kN |
| Basic static load rating C0 | 20.4 kN |
| Fatigue load limit Pu | 0.865 kN |
| Limiting speed (mechanical) | 7500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 350 g |
| Manufacturer designation | 3305 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 & 3300-series range
| Bore d | 0.984 in |
|---|---|
| Outer diameter D | 2.441 in |
| Width B | 1 in |
| ISO bore code | 05 |
| Radial section height (D−d)/2 | 18.5 mm |
| Smallest bore in 3300-series | 15 mm |
| Largest outer diameter in 3300-series | 240 mm |
| Width range across 3300-series | 19–92.1 mm |
| Bore position in 3300-series (smallest first) | 4 of 20 |
| Bore above smallest 3300-series size | 10 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 3305-A | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 25×62×25.4 mm envelope with catalogue ratings within 10 %; 3305 A is the stamped steel cage, open arrangement execution of this size — boundary dimensions interchangeable, execution differs. |
| 3305-ATN9 | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 25×62×25.4 mm envelope with catalogue ratings within 10 %; 3305 ATN9 is the glass-fibre PA66 cage, open arrangement execution of this size — boundary dimensions interchangeable, execution differs. |
| 3305-A-2Z | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 25×62×25.4 mm envelope with catalogue ratings within 10 %; 3305 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 3305-A-2RS1 model number is decoded
3305 A-2RS1 is the capped double-row angular-contact ball bearing for a 25 mm shaft, 25×62×25.4 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 25×62×25.4 mm (0.984×2.441×1 in), 18.5 mm radial section height, C 32 kN, C0 20.4 kN, Pu 0.865 kN.SKF publishes only the 7,500 r/min limiting speed for this execution, catalogue mass 350 g. The 0.865 kN fatigue load limit is the equivalent-load floor for long-life adjustment; with 32/20.4 kN ratings and 350 g mass this execution carries about 1.28 kN of C per millimetre of bore. Selection figures for 3305 A-2RS1: the static-to-dynamic ratio C0/C is 0.64, Pu 0.865 kN is about 3 % of C, and catalogue mass works out to roughly 14 g per millimetre of bore. Speed-ratio note for this exact unit: no thermal reference speed is listed (seal/grease life governs), so the 7,500 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
- agricultural machinery drives
- conveyor drum shafts
- fan and blower positions
Known failure patterns
- fine dust or moisture bypassing a worn 2RS1 lip in dirty or wet duty
- shield rubbing after misalignment or overheating of a 2Z execution
- seal-lip wear and grease loss after fine abrasive dust reaches the lip contact
- loss of controlled axial clearance (CB) after thermal growth removes residual play
- 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 3305 and capped 3305-A-2RS1 share the 25×62×25.4 mm envelope and 32/20.4 kN ratings — the choice is maintenance access and contamination, not capacity.
- Never wash 3305-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 3305: k5 on a 25 mm rotating shaft, radii clearing the chamfer.
- 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.
- Catalogue ratings are SKF PUB BU/P1 17000 figures for 3305 A-2RS1 as the double contactsealed execution; the other order numbers of the 3305 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 3305-A-2RS1?
3305 A-2RS1 measures 25 mm bore × 62 mm OD × 25.4 mm width (0.984 × 2.441 × 1 in), mass about 350 g. SKF 17000 ratings: C 32 kN, C0 20.4 kN, Pu 0.865 kN, SKF publishes only the 7,500 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 3305-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 7,500 r/min.
What is the difference between 3305 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.