3305-A-2Z bearing: complete specifications & equivalents

Specification table

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.

Cross references & equivalents

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-2Z model number is decoded

3305 A-2Z 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. -2Z marks a sheet-metal shield on each side: non-contacting, grease-retention and dust protection with negligible drag, the bearing remaining open-style relubricatable only through the shield clearance. 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 11,000 r/min limiting speed for this execution, catalogue mass 350 g. Mass and section check: 350 g inside the 25×62×25.4 mm outline leaves a 18.5 mm radial section, and the 20.4 kN static rating is 0.64× the dynamic rating — plan static safety and minimum load against those numbers rather than against sister executions. Sizing arithmetic on the 25 mm bore: 32 kN C divided by the 18.5 mm radial section height gives 1.7 kN per section millimetre; the 350 g mass and 3 % Pu/C share frame the light-load floor for the adjusted-life check. Speed-ratio note for this exact unit: no thermal reference speed is listed (seal/grease life governs), so the 11,000 r/min limiting value is the single published ceiling. Shielded execution note: the two sheet-metal -2Z covers clip into the outer ring without contacting the inner ring, giving grease retention and coarse-dust protection at virtually no friction; the cavity is factory-greased and the shield arrangement suits dry, moderately dusty positions rather than wash-down duty, where the A-2RS1 contact-seal order number is the alternative.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• The shields/seals do not make the bearing waterproof under immersion or pressure washing; select external sealing for wet or wash-down duty.
• The non-contact shields cap the speed with negligible drag: no relubrication is provided for, so mounting cleanliness decides much of the real grease life.
• Never wash 3305-A-2Z in solvent: the lifetime grease fill cannot be replaced once flushed out.
• Never wash 3305-A-2Z in solvent: the lifetime grease fill cannot be replaced once flushed out.
• Catalogue ratings are SKF PUB BU/P1 17000 figures for 3305 A-2Z as the double shielded execution; the other order numbers of the 3305 size are different products and may carry different ratings — always quote the full designation when purchasing.