7304-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 7304-ACCBM model number is decoded

7304 ACCBM is SKF's 20 mm-bore single-row angular-contact ball bearing in the 7300 series, nominal 25° (AC) contact angle, 20×52×15 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 20×52×15 mm (0.787×2.047×0.591 in), 16.0 mm radial section height, C 20.8 kN, C0 11.2 kN, Pu 0.475 kN.reference speed 19,000 r/min (thermal) and limiting speed 26,000 r/min (mechanical), catalogue mass 140 g. Load balance: C0 11.2 kN against C 20.8 kN gives a 0.54 ratio, typical of a steep-angle axial-oriented design; Pu 0.475 kN enters the SKF adjusted-life equation rather than the basic rating life. Sizing arithmetic on the 20 mm bore: 20.8 kN C divided by the 16.0 mm radial section height gives 1.3 kN per section millimetre; the 140 g mass and 2 % Pu/C share frame the light-load floor for the adjusted-life check. Speed-ratio note for this exact unit: the reference speed is 19,000 r/min against a 26,000 r/min limiting speed, i.e. a reference-to-limit ratio of 0.73. 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

• Assign interference to the rotating ring — roughly k5 on a 20 mm rotating shaft with an H7 housing — and let the stationary ring slide for axial setting; reverse the logic if the outer ring rotates.
• One 7304-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.
• One 7304-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 7304-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.