7309-BECBM 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 7309-BECBM model number is decoded

7309 BECBM is SKF's 45 mm-bore single-row angular-contact ball bearing in the 7300 series, nominal 40° (B) contact angle, 45×100×25 mm to the ISO dimension plan. 40° contact angle (suffix B): the steep standard single-row angle, giving the highest axial capacity at the cost of speed, with a recommended load ratio Fa/Fr ≥ 1. E marks the optimized internal design with an enhanced ball complement and race geometry. machined brass cage, ball-centred (suffix M), the choice for high speed, marginal lubrication and shock duty. CB means universally matchable with Normal axial internal clearance: the two side faces are ground so any two units form DB (back-to-back), DF (face-to-face) or DT (tandem) sets without regrinding. Envelope 45×100×25 mm (1.772×3.937×0.984 in), 27.5 mm radial section height, C 61 kN, C0 40.5 kN, Pu 1.73 kN.reference speed 8,500 r/min (thermal) and limiting speed 11,000 r/min (mechanical), catalogue mass 910 g. At the printed limiting speed of 11,000 r/min the mean pitch diameter dm ≈ 72.5 mm implies a dn value around 798k mm·r/min; the 8,500 r/min reference speed is the thermal-planning figure under catalogue load. Envelope economics: the 25 mm width over a 27.5 mm section yields 0.91 mm of ring width per section millimetre, and the bearing weighs 910 g for 61 kN of dynamic capacity — about 15 g per rated kN. Bore-to-OD planning: OD 100 over bore 45 is a 2.22× step for this size, and the 25 mm width gives a bore/width ratio of 1.80; use these ratios when housing space around the 45 mm shaft is the first constraint. Cage detail specific to this order number: the M cage is a one-piece machined brass window cage centred on the balls, chosen for high speeds, thin-film lubrication and shock loads; it is heavier and stiffer than the stamped Y-cage execution and tolerates interrupted oil supply far better than the PA66 or PEEK alternatives. Do not substitute the stamped-brass BECBY order number expecting identical cage behaviour.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• One 7309-BECBM locates the shaft in one axial direction only; reversing-thrust positions need a DB or DF pair — or a double-row bearing — with preload set from the load diagram, never from assembly feel.
• Mount by induction-heating the inner ring to max 120 °C; driving the bearing home through the outer ring or balls brinells the asymmetric raceway.
• Assign interference to the rotating ring — roughly k5 on a 45 mm rotating shaft with an H7 housing — and let the stationary ring slide for axial setting; reverse the logic if the outer ring rotates.
• Do not mix execution classes inside one set: a universally matchable BECBM unit is ground for arbitrary pairing, a basic execution is not.
• The steep 40° angle of 7309-BECBM favours thrust-heavy combined loads; for a predominantly radial high-speed position the 25° ACCBM execution of the same size is the alternative order number.
• Universally matchable BECBM bearings arrive ready for set mounting, not preloaded sets: preload results from how the set is clamped, so follow the SKF stand-off-ring and nut-torque procedure.