7308-BEGAPH 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 7308-BEGAPH model number is decoded

7308 BEGAPH is SKF's 40 mm-bore single-row angular-contact ball bearing in the 7300 series, nominal 40° (B) contact angle, 40×90×23 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. glass-fibre reinforced PEEK cage, ball-centred (suffix PH), keeping the polymer-cage speed advantage well above the PA66 temperature range. GA marks universal matching with light factory preload for back-to-back or face-to-face sets — stiffer than CB clearance while generating less heat than GB/GC. BEGAPH combines light-preload (GA) universal matching with a PEEK ball-centred cage. Envelope 40×90×23 mm (1.575×3.543×0.906 in), 25.0 mm radial section height, C 50 kN, C0 32.5 kN, Pu 1.37 kN.reference speed 9,500 r/min (thermal) and limiting speed 10,000 r/min (mechanical), catalogue mass 620 g. At the printed limiting speed of 10,000 r/min the mean pitch diameter dm ≈ 65.0 mm implies a dn value around 650k mm·r/min; the 9,500 r/min reference speed is the thermal-planning figure under catalogue load. Speed planning distinguishes the two published ceilings mechanically: the cage and balls tolerate 10,000 r/min while thermal balance under catalogue load sets the 9,500 r/min reference; at dm ≈ 65.0 mm the corresponding dn is approximately 650k mm·r/min. Bore-to-OD planning: OD 90 over bore 40 is a 2.25× step for this size, and the 23 mm width gives a bore/width ratio of 1.74; use these ratios when housing space around the 40 mm shaft is the first constraint. Preload and cage note: BEGAPH arrives as a universally matchable unit with GA light preload already defined for back-to-back or face-to-face sets, combined with the glass-fibre PEEK ball-centred cage for high-speed duty; it replaces field preload adjustment, not the need for correct stand-off geometry.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Greased positions should fill roughly 25–35 % of the free volume on a 7308-BEGAPH of this section and route the surplus past the outer ring; overpacking churns the grease and reproduces the thermal preload problem mechanically.
• Mount by induction-heating the inner ring to max 120 °C — the PA66 cage sets the ceiling, not the steel; driving the bearing home through the outer ring or balls brinells the asymmetric raceway.
• Keep the load ratio in the SKF design range: Fa/Fr ≥ 1 for this angle; below it the balls unload the contact ellipse and skid, which is why the catalogue insists on a minimum axial load (Fam ≈ A·(n·dm/1000)²) at high speed.
• DB pairs give the highest moment stiffness, DF pairs tolerate misalignment and thermal expansion better, DT shares heavy one-direction thrust; choose from the shaft thermal calculation rather than by habit.
• The steep 40° angle of 7308-BEGAPH 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 BEGAPH 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.