52306 bearing: complete specifications & equivalents

Specification table

Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018)) · extracted 2026-09-28

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 52306 model number is decoded

52306 is SKF's 25 mm-bore double-direction thrust ball bearing in the 52300 series to the ISO 104 dimension plan, with a flat housing seating surface, measuring 25×60×38 mm. The unit stacks one central shaft washer (ground bore, tight on the shaft), two outward-facing housing washers and two ball-cage assemblies, reacting axial force in both directions. double-direction 52/54 numbering does NOT decode the bore by the usual single-direction ×5 code — read the 25 mm bore from the dimension table; codes recur across the 522/523/524 sections and systematically trail the 51/53 code values. with no cage suffix this is the standard execution with a stamped sheet-steel ball-cage assembly (pressed cage) — the light, quiet and economical cage for small and medium thrust-ball sizes. Envelope 25×60×38 mm (0.984×2.362×1.496 in), 17.5 mm radial section, C 35.8 kN, C0 65.5 kN, Pu 2.4 kN. reference speed 2,800 r/min (thermal) and limiting speed 4,000 r/min (mechanical), catalogue mass 470 g. Preload at the mechanical ceiling: repeating Fam ≈ A·(n·dm/1000)² with factor A 0.026 at the 4,000 r/min limiting speed raises the required axial preload to about 751 N; the reference-speed value 368 N is the thermal design point. Imperial cross-check for procurement drawings: 0.984 in bore, 2.362 in OD, 1.496 in height, and the 470 g catalogue mass converts to 0.470 kg (16.6 oz). Rating split for documentation: dynamic 35.8 kN (L10 life), static 65.5 kN (safety factor s0), fatigue limit 2.4 kN (adjusted life) — three different uses of three different numbers for 52306, none interchangeable with another. Light-load floor: Pu = 2.4 kN is the equivalent-load threshold below which the SKF adjusted-life equation credits very long life for 52306; the number is 7 % of the 35.8 kN dynamic rating. Static-first selection data: 65.5 kN C0 spread across the 38 mm stack gives 1.7 kN of static rating per height millimetre, and the 470 g mass/C0 ratio is about 7 g per static kN — crane-hook and screw positions are normally sized on these two figures. Double-direction order-number note: the unit is built around one central shaft washer with a ground bore and tracks on both faces, flanked by two housing washers and two independent ball-cage assemblies; observe the assembly orientation (the two housing washers face outwards) and note that a 52-series unit replaces a mirrored pair of 51-series bearings only after the stack height and seat drawings are re-checked. At 25 mm bore and 38 mm overall height the unit drops into one recess where a mirrored single-direction pair would need two seats; both loose 60 mm housing washers must remain free to slide during thermal movement.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Torque the cover to leave the catalogue axial freedom, never solid: a clamped double-direction stack cannot float to its thermal position, and at 4,000 r/min even a small thermal thrust preload smears the hottest track.
• Service both cage sets together: replacing only the noisy side while leaving the worn 65.5 kN opposite track in place reproduces the failure within weeks — inspect both shaft-washer faces and both loose washers at removal.
• Do not replace a 52306 with two single-direction 51-series bearings without re-checking the arrangement: envelope heights, seat details and catalogue ratings differ, even at the same 25×60 mm bore and OD.
• Where shaft and housing cannot be kept square, the sphered 54-series execution of the same bore with two U seat washers is the self-aligning counterpart; the flat 52300 unit has no alignment capacity.
• Ordering discipline for 52306: the catalogue page quotes 52306 and its 35.8/65.5 kN ratings as one exact article; bare-number substitutions from another series or brand need a fresh dimension and rating check, not a like-for-like assumption.