7308-BECBP bearing: complete specifications & equivalents
The 7308-BECBP is a ISO 15 radial bearing sized 40 x 90 x 23 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 40 mm |
| Outer diameter D | 90 mm |
| Width B | 23 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 50 kN |
| Basic static load rating C0 | 32.5 kN |
| Fatigue load limit Pu | 1.37 kN |
| Reference speed (thermal) | 9500 rpm |
| Limiting speed (mechanical) | 10000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 620 g |
| Manufacturer designation | 7308 BECBP |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018) |
| Last verified | 2026-09-27 |
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.
Dimensions in inches & 7300-series range
| Bore d | 1.575 in |
|---|---|
| Outer diameter D | 3.543 in |
| Width B | 0.906 in |
| ISO bore code | 08 |
| Radial section height (D−d)/2 | 25 mm |
| Smallest bore in 7300-series | 10 mm |
| Largest outer diameter in 7300-series | 420 mm |
| Width range across 7300-series | 11–80 mm |
| Bore position in 7300-series (smallest first) | 9 of 31 |
| Bore above smallest 7300-series size | 30 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 7308-BE-2RZP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 40×90×23 mm envelope with catalogue ratings within 10 %; 7308 BE-2RZP is the glass-fibre PA66 cage, non-contact NBR seals (-2RZ) execution of this size — boundary dimensions interchangeable, execution differs. |
| 7308-BEP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 40×90×23 mm envelope with catalogue ratings within 10 %; 7308 BEP is the glass-fibre PA66 cage, open arrangement execution of this size — boundary dimensions interchangeable, execution differs. |
| 7308-BEGAPH | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 40×90×23 mm envelope with catalogue ratings within 10 %; 7308 BEGAPH is the PEEK cage, open arrangement execution of this size — boundary dimensions interchangeable, execution differs. |
| 7308-BECBM | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 40×90×23 mm envelope with catalogue ratings within 10 %; 7308 BECBM is the brass cage, open arrangement execution of this size — boundary dimensions interchangeable, execution differs. |
| 7308-BECBY | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 40×90×23 mm envelope with catalogue ratings within 10 %; 7308 BECBY is the brass cage, open arrangement execution of this size — boundary dimensions interchangeable, execution differs. |
| 7308-ACCBM | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 40×90×23 mm envelope, but catalogue C/C0 differ between executions (50/32.5 kN vs 56/36 kN) — boundary dimensions match, not a load-rating equivalent. |
| QJ-308-N2MA | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 40×90×23 mm envelope, but catalogue C/C0 differ between executions (50/32.5 kN vs 78/64 kN) — boundary dimensions match, not a load-rating equivalent. |
| QJ-308-MA | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 40×90×23 mm envelope, but catalogue C/C0 differ between executions (50/32.5 kN vs 78/64 kN) — boundary dimensions match, not a load-rating equivalent. |
| QJ-308-N2PHAS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 40×90×23 mm envelope, but catalogue C/C0 differ between executions (50/32.5 kN vs 78/64 kN) — boundary dimensions match, not a load-rating equivalent. |
| 7308 | SKF | full Dimensions and internal design equivalent — standard interchange. | SKF SKF 7308 BEP is the basic 40×90×23 mm angular-contact page with ratings within 10 % of this execution — same boundary dimensions, verify execution details. |
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-BECBP model number is decoded
7308 BECBP 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 PA66 cage, ball-centred (suffix P), with a 120 °C continuous-temperature ceiling. 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 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. Envelope economics: the 23 mm width over a 25.0 mm section yields 0.92 mm of ring width per section millimetre, and the bearing weighs 620 g for 50 kN of dynamic capacity — about 12 g per rated kN. 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. Universal polymer-cage execution: BECBP is the factory-ground set-mounting version of the basic BEP — both side faces are finish-ground to a controlled stand-off so two units form DB, DF or DT arrangements without shims, while the glass-fibre PA66 ball-centred cage keeps the light, quiet running typical of the P-cage range; CB delivers Normal axial clearance before preload is applied at assembly.
Typical equipment & failure modes
Common applications
- test-rig and balancing-machine shafts
- machine-tool spindles and spindle units
- servo drives and precision gearboxes
Known failure patterns
- fretting at the ground set faces of a universal pair whose clamp torque relaxes
- raceway spalling from axial overload beyond the single-direction thrust rating
- ball skidding when Fa/Fr stays below the 1,0 (40°) or 0,55 (25°) ratio and the contact ellipse is unloaded
- PA66 cage embrittlement inside a preloaded set where heat accumulates faster than in a single mounting
- edge loading from shaft deflection or housing misalignment
- brinelling from pressing the ring home through the balls or from static overload
Selection pitfalls — read before you substitute
- 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.
- Greased positions should fill roughly 25–35 % of the free volume on a 7308-BECBP of this section and route the surplus past the outer ring; overpacking churns the grease and reproduces the thermal preload problem mechanically.
- 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.
- Greased positions should fill roughly 25–35 % of the free volume on a 7308-BECBP of this section and route the surplus past the outer ring; overpacking churns the grease and reproduces the thermal preload problem mechanically.
- The steep 40° angle of 7308-BECBP 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 BECBP 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.
Frequently asked questions
What are the dimensions and catalogue data of 7308-BECBP?
7308 BECBP measures 40 mm bore × 90 mm OD × 23 mm width (1.575 × 3.543 × 0.906 in), mass about 620 g. SKF 17000 ratings: 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).
What does the BECBP suffix mean?
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 PA66 cage, ball-centred (suffix P), with a 120 °C continuous-temperature ceiling. 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.
What minimum axial load does 7308-BECBP need?
The balls must remain seated: SKF gives Fam ≈ A·(n·dm/1000)² and a load-ratio guideline of Fa/Fr ≥ 1 for the 40° B execution and ≥ 0,55 for the 25° AC execution. Preloaded pairs and spring loading are the usual ways of meeting it at light load and high speed.
What is the difference between BEP, BECBP and BECBM?
All share the 40° optimized geometry: BEP is the basic PA66-caged single bearing, BECBP adds CB universal matching (ground faces, Normal clearance) with the same PA66 cage, and BECBM is the universally matchable version with a machined brass cage for higher speed and temperature.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018) on 2026-09-27. Read our editorial & correction policy.