52309 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 52309 model number is decoded

Listed in SKF 17000 chapter 5, 52309 is an ISO 104 double-direction thrust ball bearing, 35 mm bore and 85 mm OD on a flat housing seat, standing 52 mm high before installation. Construction is a five-component stack: one central shaft washer with tracks on both faces, two outward-facing housing washers and two cage sets, which lets one housing recess accept thrust from either direction. note the bore of 52309 is 35 mm by the dimension table: the double-direction series was deliberately aligned to the 51/53 washer sets with shifted codes, so the familiar 04=20 arithmetic does not apply here. no cage suffix means the standard stamped steel retainer — a pressed sheet-metal ball-cage assembly that covers the bulk of the thrust-ball assortment. Envelope 35×85×52 mm (1.378×3.346×2.047 in), 25.0 mm radial section, C 76.1 kN, C0 153 kN, Pu 5.6 kN. reference speed 2,000 r/min (thermal) and limiting speed 2,800 r/min (mechanical), catalogue mass 1250 g. Selection figures for 52309: the C0/C ratio is 2.01, Pu 5.6 kN is about 7 % of C, and the catalogue mass works out to roughly 36 g per millimetre of bore; the printed minimum-load factor is A 0.12. Section proportions: the 25.0 mm radial section compares with 35 mm of bore (section/bore ≈ 0.71) and the 52 mm height is 2.08× that section — the proportions that identify the 52300 envelope at a glance. Static-first selection data: 153 kN C0 spread across the 52 mm stack gives 2.9 kN of static rating per height millimetre, and the 1250 g mass/C0 ratio is about 8 g per static kN — crane-hook and screw positions are normally sized on these two figures. Minimum-load arithmetic: with dm ≈ 60.0 mm and factor A 0.12, Fam ≈ A·(n·dm/1000)² at the 2,000 r/min reference speed is about 1.7 kN for 52309; below that preload the balls skid and smear the tracks. Bore-to-OD planning: OD 85 over bore 35 is a 2.43× step for this size, and the 52 mm height gives a bore/height ratio of 0.67; use these ratios when the housing recess around the 35 mm shaft is the first constraint. 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 35 mm bore and 52 mm overall height the unit drops into one recess where a mirrored single-direction pair would need two seats; both loose 85 mm housing washers must remain free to slide during thermal movement.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• The central shaft washer takes the interference fit on the 35 mm shaft while both outer housing washers run loose in their registers; both loose washers need positive axial retention on vertical shafts.
• 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.
• Each direction independently needs the minimum axial load (factor A 0.12): the side that is momentarily unloaded during slow reversal skids first, so arrange preload or symmetry rather than assuming the loaded side drives the idle side.
• Service both cage sets together: replacing only the noisy side while leaving the worn 153 kN opposite track in place reproduces the failure within weeks — inspect both shaft-washer faces and both loose washers at removal.
• Ordering discipline for 52309: the catalogue page quotes 52309 and its 76.1/153 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.