7308-ACCBM 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-ACCBM model number is decoded

7308 ACCBM is SKF's 40 mm-bore single-row angular-contact ball bearing in the 7300 series, nominal 25° (AC) contact angle, 40×90×23 mm to the ISO dimension plan. AC sets the 25° contact angle, CB marks universal matching with Normal axial clearance, and M the machined brass ball-centred cage. 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. 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 40×90×23 mm (1.575×3.543×0.906 in), 25.0 mm radial section height, C 56 kN, C0 36 kN, Pu 1.53 kN.reference speed 10,000 r/min (thermal) and limiting speed 15,000 r/min (mechanical), catalogue mass 680 g. Mass and section check: 680 g inside the 40×90×23 mm outline leaves a 25.0 mm radial section, and the 36 kN static rating is 0.64× the dynamic rating — plan static safety and minimum load against those numbers rather than against sister executions. The 1.53 kN fatigue load limit is the equivalent-load floor for long-life adjustment; with 56/36 kN ratings and 680 g mass this execution carries about 1.40 kN of C per millimetre of bore. Speed-ratio note for this exact unit: the reference speed is 10,000 r/min against a 15,000 r/min limiting speed, i.e. a reference-to-limit ratio of 0.67. High-angle alternative note: ACCBM carries the 25-degree AC contact angle (not the 40-degree B), CB Normal-clearance universal faces and a machined brass cage; it runs faster and cooler than a BECBM of the same envelope but accepts a smaller axial share, so substitute only after re-running the load-ratio check.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• 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.
• Greased positions should fill roughly 25–35 % of the free volume on a 7308-ACCBM of this section and route the surplus past the outer ring; overpacking churns the grease and reproduces the thermal preload problem mechanically.
• One 7308-ACCBM 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.
• Keep the load ratio in the SKF design range: Fa/Fr ≥ 0,55 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.
• The 25° AC angle of 7308-ACCBM runs faster and cooler than a 40° B bearing of the same envelope, but its thrust capacity and induced-load behaviour differ — do not swap AC for B without re-running the axial-load calculation.
• Universally matchable ACCBM 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.